Just competed the job, and what a job!
I decided to change the hubs and not the entire trailing arms as the ones from my doner car were twisted. Big mistake. The ones from the younger, doner car came off pretty easily but when it came to my car it turned out to be a 'worst case senario'. The heads were rusted all to hell(15years old, uk weather) and kept rounding so i decided to drill them out: mistake number 2. I have never drilled anything as hard in my life. Blunted about 10 drill bits just drilling 4 bolts. i still had to chisel them off the last bit. Heating them up just seemed to make them harder.

When it came to the other side i had a bit of extra thinking time and decided on anthother method, which i cannot reccomend stongly enough. With the trailing arm removed and in a vice, with the hub resting on the bench, i heated them till they were cherry red(even the tops melted they had to be that hot), left them to cool sufficiently and used a good, 1/2inch drive impact driver held in either a large pipe wrench of a small vice(free, not fixed for inertia) and got an assistant to use a large hammer on it with a brand new star drive and all four came out.
DO NOT go near them without doing this as you dont want to have to drill them out, belive me. If, as a last resort you do have to, then from experience i believe the best way would be to run a 7.5mm drill bit down all 4 as they fit past the splines and get a sharp chisel or decent screwdriver between the hub and trailing arm and pop them off with a big hammer, being careful not to damage(or bend) the arm.
Just thought id share my fiindings and i hope they come in usefull.

 

sorry, i meant OR a small vice. Good mecanic, bad typist i guess!

 

lol, i just went through close to the same thing, i was pulling off my lower control arms too, not to convert to disk, but i had to change some bushings. Most of the bolts went fine, the only major problem i have now is one of the bolts that mount the "big" bushing to the frame of the car. i broke it trying to get it off
If I would have known it would have been this much trouble, i would have never taken them off in the first place