This is the first time I've every done this, I have a 92 RS with a 10 bolt rear end with drums. I just ordered a conversion kit for discs but the instructions are not very good. I got the housing open, removed the retaining bolt and the big center bolt. After these were removed I was able to rotate and remove the little gears that the center retaining bolt went through. In other video's I've watched, these gears have shims or washers with them, but mine do not. It almost looks like the shims are attached to the back, is this correct?
Now on to removing the drums. I managed to wiggle out the c-clips without removing the drum cover, but I still cannot get the drum and axle off. Are there bolts I am missing on the back side that need to be removed?

 

If the c clips are out the axles should slide out. Obviously you said the drums are still on it and they will not come off either. Do they turn? If so you might need to just get very physical with them. I have been known to carefully use a small sledge to remove drums before.
If the drums do not turn then they are froze to the shoes.
I would have pulled the drums off first but that should not have actually mattered.

 

The drum cover deal came off when I managed to wiggle the axle out. I am now trying to get the backing plate off and I can't for the life of me get the anchor pin out and that seems to be the last bolt that is holding everything together. Any suggestions?

Also, the little gears that had to be removed from the differential did not have shims, but it almost looks to me like they are attacked. Does anyone know if this is correct? As far as I know this is the first time the diff has been opened.

 

The shims are attached to the gears by hydraulic pressure... They will slide right off. Kind of like a suction cup needing to be wet to stay in one spot (for a while).

If you're converting to discs anyways, cut the anchor pin off. IIRC, you're going to need to modify the backing plate mount anyways. Did you remove the lower bolts in the backing cover yet? DON'T BREAK THEM!!!