Instructions
Head toward Gerudo Valley; you will find your path blocked by a broken bridge. To get across the bridge, shoot your longshot at the wooden stake on the other side of it. Alternatively, if you are riding the horse, Epona, jump over the bridge.
Speak with the carpenter near the tent. Climb off Epona and proceed on the path to the fortress.
Allow yourself to be captured by Gerudo guards as soon as you get closer to the fortress. You will next find yourself in a jail cell from which you will need to escape.
Shoot the longshot at the wooden panel above the window. Enter the fortress through the first door on the left.
Navigate the Gerudo Fortress without getting caught by Gerudo guards. Otherwise, you will return to the jail cell and start over again.
Talk to the carpenter in the jail cell. Fight the Gerudo Thief who appears for a surprise attack immediately after this conversation. Defeat her and take the key that she leaves behind her. Unlock the carpenter's cell with the key to set him free.
Leave via the path that goes outside. Go through the door on top of the ledge. Speak with the second carpenter in his cell. As with the first carpenter, you must defeat another Gerudo Thief and take the key she leaves behind her to set the carpenter free.
Take a path that you did not previously take to exit the room. Drop down to the lower ledge and enter through the door that you find there. Find and talk to the third carpenter. Defeat the Gerudo Thief and open the carpenter's cell with the key that she leaves behind her. Leave the room from which you came.
Climb the vines outside to reach the topmost ledge. Find the last door and enter it. Stay behind the large crate until the guard passes, and then run past her to the fourth jailed carpenter.
Talk to the carpenter, and then fight the last Gerudo Thief. After you defeat her, she will commend your work and grant you a Gerudo membership card, which allows you access to all the areas of the fortress as well as the Haunted Wasteland.