The Main Courtyard
You will be attacked by Sentinels again once you get outside, destroy them as you make your way along the bridge and parapet. When you get to the far end of the parapet, before you go through the doorway back into the Main Courtyard, climb up the ladder to the right of the doorway. This is a very long ladder, and you'll be coming straight back down, so as long as you don't stand around looking at scenery at the top, you should leave Yorda at the bottom. Climb the ladder and go through the doorway at the top. It leads to a platform far above the Main Courtyard. Run over to the right and pull the lever (which lowers a drawbridge), and then go back down to Yorda the way you came without delay.
Go through the doorway next to the ladder into the Main Courtyard. Go across the drawbridge you just lowered, and follow the walkway on the far side all the way over to the left. At the end you should find a crate. Push/pull it right until it is next to the nearest pillar. Climb up onto the crate, and then up onto the pillar. Jump over towards the rope to the right, and swing your sword at the same time to cut it. This will lower a rope into the lowest part of the Main Courtyard.
Start climbing up the rope, and note the broken window across from you. Ignore that one, and climb up to the window one floor up, which is also broken. When you are level with it, jump over to it. Drop onto the narrow walkway just inside the window, and follow it into the room over on the right. Push the crate in this room into the room below, and drop down after it. Move the crate over to the broken window in this room, and then push it through the window, down into the courtyard. Help Yorda to climb into this room using the crate. Take her up the stairs across from the broken window, get her to open the Idol Doors, and go through.
Written by Crumplecorn