I just went to the garage to make sure I don't give you wrong information. This is from my 85250R(same).
Have assistant sit on bike and firmly apply rear brake. Turn large nut towards the back of the machine(if you are lifting the machine up that is the wrong direction). Back the large nut off untill it is about 3/4 of the way on the threaded collar. Turn the smaller nut same direction until you can slide the 'c' clip retainer towards the axle bearing carrier. Remove the 'c' clip and everything will slide off of that side including the disc brake hub once the caliper is removed. If machine was ridden in mud, water, moisture, stuff may be rusted together. Go ahead and use a little heat to try and break things loose. Hope this helps. Oh, If still rested together, maybe a cutoff wheel to remove large jam nut. Or an air chisel to "jitter" the large nut off. As an auto machanic I have used that trick on many rusted parts.

 

I would spray a BUNCH of wd-40 on it then bust out the torch. ha ha that would be cool.

 

I had the exact same problem, but I couldn't get the nut off without taking the whole swingarm off, while the axle was still installed. I put the whole thing in a vise, used a propane torch, WD-40 and lots of elbow grease! I didn't damage a thing, and I got it all off. If you used an oxyacetylene torch, it would probably cut the nut off, which is OK if you don't want to use it anymore.

 

we ended up taking a cut off wheel and a grinder and cuting just the smaller nut off and it all sliped right out thanks for all the reply's

 

ya just want to head it not cut it off.....using the torch is good.....just don't touch the oxy lever....as you heat steel it expands....then move it with a spanner or something....its the easiet way i have found to get those nuts off....its works ok....just don't point the heat at the bearings etc.....ya will know for next time anyway.....put insulation tape around the nuts when you put them back on.....i find it keeps the moisture out better.....making them easier to remove next time