Dashboard veterans, please help !

I'm taking an embarassingly long time just to get the dashboard off my 88 GTA so I can check out a burned wire in a loom down at the driver's feet, in the corner by the fuse box. I can actually pull the loom down about an inch and get a good look at part of the problem area, but its pretty awkward, so I want to take out the dash to get at the loom better, maybe even remove it, if possible.
The loom was rubbing against the driver's side mounting bracket for the tie bar, and there is actually exposed copper now !! And a blowing fuse and fusible link.


I've hit a brick wall, though, on getting the dashboard out. Stumped at this point.



What I've done so far :

1. Removed dash pad.

2. Removed a few trim panels on the bottom of the dash.

3. Removed the box on the bottom left of the dash for fog lights.

4. Loosened bolts holding the tie bar to the 2 corner brackets (although I think thosee bolts could stay tight). The tie bar is the metal strip under the dash that holds it up.

5. Removed instrument cluster. After I removed the screws, it just came right out, no wires !! Just contact connectors! Easy.

Now I can shine a flashlight down into the gaps and see the looms and where the burned wire goes, but I need to get at the loom to perform surgery on it.

So, at his point, I still have all the defroster stuff hooked up to the dash, which I think is OK. I have the dash totally off, at the top, the windshield side, and I can rock it back and forth. But there must be some screws somewhere on the tie bar under the dash holding it on, because it won't come off the tie bar.

I noticed two round button-shaped flat things on the lower left face of the dash under the fog light buttons on the driver's side. I reached around behind these buttons and felt something like a nut. What the heck? Are these rivets ?? They seem to be holding the dash panel onto the tie bar, but the Chilton's doesn't mention them. How do I get rivets off? Geez...

Another question : I removed the radio trim plate, and saw 2 screws just above the radio, and below the temp controls. DO they need to come out ? I started to take them out, but the radio started to move, so I thought they must just be for radio mounting.

Thanks for any help !