After reading various sources including the Haynes manual, it's still not completely clear to me how much of the fairing/headlight assembly has to be removed to get the speedo assembly out on my RT. Could someone who's done it give me an idea of what pieces I need to remove? I want to be able to gain access to the contacts that connect the cables to the unit and do maintenance on them.

HI claudejones
I have an 85 RT, and only had to do smallish work to get the whole instrument cluster off.
Undo all the screws and remove the windshield.
You can get at the wiring contacts from the front of the bike. You have one small screw to remove a plastic shield covering the back of the 2 wiring connectors. This screw is awkward to put back in later, I filled the head with candle wax and stuck in onto a short phillips head driver to get it back in. Once the shield is off, just wiggle either connector up and down a bit, they pull off towards you.
Then there are four hex nuts o remove from the back of the unit,
you are taking the cluster off the support frame, not the whole frame. Turning the steering head to the side gives access, but a short socket driver helps. DONT DROP ANYTHING. I lost the little screw in there somewhere and I'm sure it'll end up in my front tyre.
Hope it helps
RT