The left right hinge is broken, how to fix?

Titanium screens can be replaced, but it's not easy -- you literally have to remove the logic board in order to take out the screen assembly. I've done a few of these over the last few days, and I can say you're definitely in for a good hour of work. iFixit has a good guide for this...just make sure to keep the screws in order and take the process one step at a time, because it's one of the hardest repairs and can be a little overwhelming.

Honestly it's not worth trying to use the same screen by trying to put your existing screen in another screen frame. The bezel is glued onto the screen, and for the life of me I've never been able to salvage one, and they always get bent up when removed. Your best bet is to buy a dead Titanium on eBay for $50 that has a good screen assembly (screen, bezel, and hinge), and just transplant the whole thing. Similarly, you can remove your current screen from the broken frame and hinge, and sell it again on eBay in order to make your money back. The Titanium 15" screen works on Aluminum 15" PowerBooks (I just used two screens from dead Titaniums to repair two Aluminums with bad screens!), so you can advertise it as such, and there are more than a few buyers out there.