I have a 91 Lumina, my question is; how do I open the hood when the latch is broken

What part broke the handle or cable in the cab or the latch itself under the hood. If the handle is broken try to get a pair of vise grips on the cable. If the cable is broke the easiest way is going to reach up from the bottom to the cable and cut it as close to the cab side (away from the latch) as possible then strip some of the jacket off the cable, once exposed get a pair of vise grips on the cable and pull away from the latch. If the latch is broke you will need to try a pop it with a pry bar or screwdriver. Try looking up some images of it. I've never had to do it on my own cars but on plenty others and yeah not fun.

My first beretta came with the cut cable with a knot tied in it and it stuffed out under the hood above the head light so someone had fun with it.