Since you have a 92, you probably have the glass held in with urethane. You can check by removing the nuts and pushing up on it. If it moves, the sealant is butyl. You have to remove, or at least loosen, the front of the roof rack to get the glass out. You may find some "fun" things when removing the roof rack. I can give you some guidance as you progress. My evenings during the week are the best times to contact me.
If it is held on by urethane, you need a special knife to cut it loose. Most auto paint stores have the knife...it is an extremely long narrow box cutter.
Removing the headliner is almost a necessity to get to the roof rack bolts. Be careful with it, it is easy to break along the sides of the vista window. While you have it out, you should fiberglass the back side of that area with some 2-3 oz. glass cloth.
Once you have the front of the roof rack off, you can pull the glass. Check for rust along the back of the rear glass support. If it is rusty, fix it before installing the glass.
If the glass is urethaned in place, tape the edges around the vista window opening so you do not slice your hand open when cutting the ruethane... it is tough, and you WILL slip. Since you are replacing damaged glass, you can cut it from inside or outside. Protect your paint if you are working from the outside. The reveal is cast onto the glass, and can not be removed without damaging the reveal from the outside.
Once you have the old glass off, make sure the surface is properly prepped for urethane if you are going to use it. If you are going to use butyl, just clean it very well.
There are a lot of nitty gritty little things involved, and it is easier for me to walk you through them as they happen.