Enerpro window latch

Start by looking at our 38-092 lock. I believe this is the one you need, but our 38-091 is another possibility. You may want to look them both over to be sure. 

As for installation instructions, there really isn't any. You will need to get the window unlocked to access the mounting screws from the back side of the lock. If your window is locked already and can't open, then you'll need to find some way to force the lever handle back into the lock and see if you can unlock the window. If not, I recommend contacting a local professional. You'd have to drill or possibly cut the lock off to remove it, which is a very difficult project.

Ah, great. That's just what we need to see. I think the 38-091 and 38-092 I mentioned look pretty similar in design to your locks, but see if our dimensions match up to yours.