So just as the title says, In the state of maine, the horn needs to work to pass safety inspection. It is a 1991 Trans Am GTA and the center piece is peeling back at the corners like a lot of our cars. I assume that the ceneter piece peeling back is the cause of the horn malfunctioning so how would I go about removing/ replacing it... can I do that? There are also not any salvage yards around here si I'm not sure where I would get the piece if it is replaceable. Any suggestions? Pics if requested.

You have checked the fuse right?
If you just need a quick workaround you could get a push button type switch and wire it to send ground to the black wire in the steering column harness. Not the ignition harness, the smaller one that sits on top of the column.
A valet switch from an alarm would do the trick just fine. One wire goes to ground, the other goes to that black wire. Run the wire up to the back of the steering wheel, and possibly even slip it under that peeling back corner. I'm not suggesting this as a permanent fix, just a workaround to get you through the inspection.

how would I go about taking the big square centerpiece off the steering wheel to get to these wires?

Four screws on the back side hold the center piece on. When you get it off, you may find the horn switches behind it have deteriorated and are causing your problem. The switches and harness are available at sites like Hawks and are easily replaced. My 91 did the same thing and I think the part was about $15.
Good luck.

Not to hi-jack your thread but i have the same problem with my 91 camaro. The fuse is fine, the horn works when hard wired... but it doesn't work when i push the two buttons on the steering wheel... has anyone had this issue with their 91 camaro too?

yeah...i have the same exact problem. only thing is i cant find the horn on any of my wiring diagrams...so its hard to put a new switch in since i dont know the wire colors. if anyone could help me out and lemme know:

1) where the actual horn is located
2) what color the wire from the wheel to the horn is

1) the horn is located under the left fender, behind the battery, in that sort of area. There are two of them.
2) The wire doesn't run directly from the horn button to the horn, it goes through a relay. But the common wire around there connecting the two horns is green.

Had same problem with a car years ago, wasnt a problem till inspection. Until you can properly fix it go to a parts store and buy a horn button and mount near steering wheel. Run 2 wires and your ready for inspection. Then you can take your time fixing horn right.