You find no way into the Spirit Temple, but Sheik teaches you a melody to warp to the Desert Colossus, even as a child.
Get a Gold Skulltula
Equip the Hylian Shield to avoid losing your Deku Shield to flames in this dungeon.
Go up the stairs and go to the left. Talk to the Gerudo. Her name is Nabooru. When she asks you a question, say "Nothing, really", then say that you hate Ganondorf. Agree to help her. Make sure that your slingshot is equipped, and crawl through the hole.
In the next room, use the slingshot to kill the Keese, then go past the Razor Trap and go up the stairs. Kill the other two Keese in the room, then awaken the Armos statue by hitting it or going near it. Kill it with a bomb or a bombchu. The doors will open. Go through the one on the left.
Carefully kill the Stalfos. You are weaker to its attacks as a child. Then approach the gap, and kill the green Bubble when its flames disappear. Then you have to use the boomerang to hit the switch behind the metal wall up ahead. Look slightly to the left of the switch and throw the boomerang. If you don't hit it, keep adjusting your position until you do. When you hit it, the metal thing will fall and create a bridge. Go across and shield yourself from the flying pots next to the chest, then open the chest to get a blue rupee. Then go through the nearby door.
There is an Anubis in this room that will spit flames at you if you get close. You can block the flames with the Hylian Shield. Anubis will mirror your movements. You have to kill the Anubis to proceed to the next room, and it is only vulnerable to flames. If you have Din's Fire, you can approach the middle of the platform and use it to kill the Anubis. If you don't have Din's Fire or don't want to use it, you have to hit the crystal switch, then walk around to make Anubis mirror your movements and float into the flames. Go through the door that opens when you kill the Anubis.
There is a Wallmaster in the ceiling, so don't go too far into the room at first. Kill the one Keese that is on this side of the fence, then go farther into the room to lure the Wallmaster down and kill it. Then target the Keese on the other side of the fence and use the Boomerang or Slingshot to kill them. Collect the silver rupees. One is behind the torch in the corner. The bridge will fall. Go across it, then turn around and use the Boomerang to kill the Gold Skulltula.
Get a Key
Then light a Deku Stick with the torch and light the two unlit torches. A chest will appear. Open it to get a small key. Go through the door near the two torches that you lit a moment ago.
Get a Second Gold Skulltula
Back in this central room, crawl through the hole between the torches and unlock the door. Kill the skulltula on the wall, then look up at the climbing wall and kill the Skulltula there with the boomerang. There is a Gold Skulltula farther up. Climb up the bricks, then turn around and hit the Gold Skulltula with the Boomerang to get its token.
Get the Map
There are two Lizalfos hiding in this room. Go around the room to make them appear, then kill both of them. If you don't have any Bombchus, hit the crystal switch to make two chests fall. One contains Bombchus, and the other contains a blue rupee. Then use the Boomerang to kill the Skulltulas near the sunlight coming from the wall. Finally, use a Bombchu on the rock near the sunlight. You can target the rock for more accurate aim. The door across from the sunlight will open, so go through.
Turn left and push the Armos statue off the edge, and it will land on a switch. Go up the stairs, and before going through the door, light a Deku Stick and jump to the bottom floor, go to the center, and light the unlit torches. A chest will appear. It contains the map. Climb up the wall next to the Armos statue that you pushed off earlier, and go up the stairs and go through the door at the top. In the curved corridor, go through the next door.
Get a Second Key
Bomb the three Beamos so you can move safely around the room, avoiding the Razor Traps. Collect the five silver rupees to light the torch. Go around the room to see where the three unlit torches are, then light a Deku Stick and go around lighting the torches. A chest will appear. It contains a key.
Go to the Miniboss
To go to the next room, move the grey blocks around until you can pull the sun block out. Then move the sun block under the sunlight. Go through the door that opens.
Go part of the way up the stairs, then turn around and kill the Gold Skulltula above the door that you just came through. After you take the token, go up the stairs and go through the locked door.
Iron Knuckle
There is an Iron Knuckle sleeping in this room. If the Iron Knuckle hits you, you will lose four hearts. Hit it with your slingshot or boomerang to wake it up. You have to target Iron Knuckle and stand near it, then jump out of the way of its axe. Sometimes it swings the axe side to side, but sometimes it swings it downward, getting it stuck in the ground. Hit Iron Knuckle repeatedly while its axe is stuck in the ground.
If you take a lot of damage, stand behind a column or the throne. Iron Knuckle will hit it with the axe, releasing three hearts.
After you have hit Iron Knuckle several times, part of its armor will fall off, allowing it to move more quickly.
Continue fighting it carefully until you defeat it.
Get the Silver Gauntlets
Go through the door behind where Iron Knuckle's throne is (or was), and go outside. You will be standing on one of the Desert Colossus's hands, where you see a chest. After the owl talks to you, open the chest to get the Silver Gauntlets.
Then there will be a cutscene. Afterward, if you are ready to complete the Spirit Temple, play the Prelude of Light to go to the Temple of Time, or just save and quit outside to start the game in the Temple of Time when you load your save file. Then pull the Master Sword to go forward in time. Play the Requiem of Spirit to return to the Spirit Temple, and go inside.