As in, you're installing a whole new tray? If I remember correctly, it's connected to a piece of plastic that has places for screws on the right side of the PS2 disc drive. It's connected to a metal rod, which is connected to a chain and a motor. Move that plastic piece part towards the front as far as it will go, line up the holes in the tray and the holes in that piece and screw them together. Now, you should be able to move the tray up and down since it's only attached to the right side. With it still completely extended, lay if flat, and try pushing it in. There's grooves in the bottom of the tray, and a white circle that has grooves on it. You have to get them to align. After you get them aligned, reassemble the PS2 and turn it on and let it do it itself. Test it a few times so that you know it will work. If you're talking about a tray that has just gotten stuck in normal use, then it might be that it's just gotten off track. If you don't want to disassemble your PS2, try working the drive in and out with or without the motor's help. You'll have to be sort of forceful, but not so forceful that you'll break anything. (Apparently, this is what my brother did out of pure desperation when our PS2 stopped working and it worked. We later learned that sometimes Sony Tech actually suggests this.) However, it could be something else, like a motor problem, or the rod that the plastic piece moves on isn't greased enough. There's tons of guides on the web that can tell you how to do that if you find you need to go that far. Good luck. Hope this helps!