George
Well, hopefully my instructions will at least help get this other radio wired (power/ground, etc) If you need me to, I can figure out which one is constant power source (for radio memory and clock, if it has that) and which one is switched power.
I'm not familiar with the radio you mentioned. If "96" is the year then it takes a code. If this is what the radio is, do you HAVE the code (let me know).

Just leave the wire alone for the anti-theft alarm that I mentioned (with the white connector) but I'd tape that metal tab with electrical tape.

If you can remove the speakers it may make it easier to wire them to the radio, this should work if you will be happy with front speakers only. This assumes the amp is built into this radio you want to install. Can you post an image of the front and back of the new radio?

If this new radio uses the typical MB speaker connectors you'll probably have to get speaker connectors like what MB uses (your cars speaker wiring must run back into the trunk). I have a couple of them around I think, but you said you need this done fast.
You may also be able to find the ones that plugged into the receiver/amp in the trunk.

Gilly