Go to the Tower of Spirits after you leave the Ocean Temple and head up the stairs to Floor 13.
First Tear of Light
Go to the right and avoid the Phantom. Use your boomerang to light the unlit torch to the right, making a chest appear up above. Then use the boomerang to stun the Phantom Eye and reach the first Tear of Light.
Second Tear of Light
Go to the upper right part of the room, walk up the stairs onto the platform, and stand on the upper left corner. There are whip poles to the left. Carefully whip your way to the second Tear of Light. Make sure not to whip over when the Phantom Eye is nearby or it will see you while you are swinging on the whip. You can't avoid letting the eye next to the Tear of Light see you, so just run over to the Tear of Light in the safe area as soon as you land, and it will not be able to see you. Kill it, then be sure to stay in the safe area so that the Phantom that warps over won't see you. After you kill the Phantom Eye and wait for the Phantom to warp away, you can leave.
Third Tear of Light
Go to the upper-right corner fo Floor 13 and walk into the safe spot with the crystal switch. Activate the switch to create a bridge. Then go around to the treasure chest that you revealed to get a small key.
Go up the stairs onto the platform and use the whip to put the sword into the rightmost face. This reveals a treasure chest that contains a small key. Do NOT put the sword into the leftmost face because this will create a Phantom near the treasure chest that you just revealed.
Go back to the lower left area and up the stairs, across the bridge, and open the treasure chest that appeared. It contains another small key. Jump down and use the key on the locked door. The crystal switch won't do anything right now, so just go back to the upper right area and unlock the door there and go up the stairs.
Upstairs, use your boomerang to stun the Phantom Eyes in your way. Then when you get close to the Phantom, hit a far wall with your boomerang to make the Phantom go over and investigate, then quickly run behind it and get the third Tear of Light. Then when the Phantom goes back to its spot, you can hit it in the back.
Warping Around
On floor 14, have Zelda warp to the Phantom Eye in the closed room. Just draw a line from her to the Phantom Eye so that she targets it. She will warp over to it. Have her step on the switch to open the door. Then have Link go in, avoiding Phantom Eyes on the way or just having Zelda kill them, to get a random treasure from the chest.
Now go back down to floor 13. Have Link walk up onto the raised platform that you stood on to reach the second Tear of Light, and have Zelda stand on the floor below. Have Link jump onto her shield, then have her walk over to the whip platform just below the treasure chest on the right side of the room. Have Link whip up to the treasure chest to get a random treasure.
Now have Zelda warp over to the Phantom Eye in the upper left area of floor 13 that you can't reach. Just draw a line from her to the Phantom Eye so that she targets it. She will warp over to it. Have her walk down to the crystal switch.
Switch to Link and have him walk to the other crystal switch in the lower left corner of the area. Have him hit the crystal switch and then quickly have Zelda hit the one that she is standing next to. The door will open. Have Link go up and join Zelda and call her, then go up the stairs.
Have Zelda kill the two chuchus that get in your way. Zelda will sink if she walks over the sand, but Link can safely go over, so have Zelda stand on the switch to the left of the sand, then have Link stand on the one to the right of the sand.
Have Zelda walk across the spikes and then stand on the circular thing on the right side. Have Link walk to the right and stand on the other circular thing. The two of them will switch places. Have Link use the whip to move the sword from one face to the other. Then have Zelda walk over the spikes to Link, and have the two of them go up the stairs together.
Floor 15
On floor 15, have Zelda walk over the spikes on the right and go around to the yellow triangle down below. Then have Link stand on the other yellow triangle to warp over to the other side. Have Link run up over the sand on the right side of the room.
Push the block onto one of the two floor switches. Then Have Link go over and stand on the blue square on the floor. Have Zelda walk onto the other blue square, which is above the yellow triangle that she stood on a moment ago. Once Zelda has switched places, have her step onto the floor switch that Link didn't push the block onto.
Switch to Link and have him walk over the spot where the spikes were so he can reach the double door at the upper right corner of the room. Have Zelda walk over and join him there. Have Zelda target one side of the door, then have Link tap the other side. Get the small key from the chest.
Now have Zelda stand on that blue square on the floor again, and have Link go up the short stairs and hop down. Have him walk onto the blue square to switch places. Then once again, have him walk up the short stairs and hop down.
Have Zelda warp over to the Phantom Eye on the left side of the room. Have Link walk to the area just across from the gap in the floor south of where Zelda just warped. Have him use the boomerang to create a bridge over the small area of sand for Zelda to walk across.
Have Zelda walk to the southernmost part of this area, killing the chuchu here. Have her walk to the right to step onto the red circle tile, then have Link walk onto the other red circle tile on his side. Have Zelda walk down past the two switches and have her step on the lowest switch to lower the spikes so Link can exit this area.
Have Zelda stand in front of the rolling boulders so that Link can get over to the switches to the right of the spikes. Have him stand on one, then have Zelda stand on the other to create a bridge back to the center area.
Before leaving the left side of the room, have Link go up and use the boomerang to push the Phantom Eye across the upper area of sand, then have Zelda warp to the Phantom Eye when it's on the left side of the sand. That way, Zelda can stand on one of the two floor switches there even though there's no way across the sand. Then have Link run over and stand on the other switch. This will open the door in the middle of the room.
Have Zelda warp to the Phantom Eye in front of the door that you just opened, then have Link run over to her and the two of you can go up to floor 16.
Floor 16
The sign up ahead says to move from the green tile to the red tile to form a special symbol. Have Zelda warp to the Phantom Eye on the right side of the room and target the Phantom walking around. The Phantom will say that the path that it is taking has a special meaning. Watch the way that it walks and make a note of the path on your map. Then have Zelda warp to the left side of the room and walk along the same path as the Phantom, starting with the green tile. It doesn't have to be exact, as long as it follows the same path as the Phantom on the right. If you do it correctly, the door in the middle of the room will unlock and you can go upstairs.
Floor 17 is where you receive the Fire Rail Map. However, after you get it, a certain someone appears. Once the cutscene is over, you should go toward the Fire Sanctuary. Start by going to the Snow Realm.