Hi John. Well the good news is that the rear drums will rotate. The bad news is that if both star wheels are broken, getting enough slack in the shoes to slip past the ridge on the drum isn't so easy. Will the drum move outwards at all as you turn the drum at the same time? Sometimes you can get the drum to move away from the backing plate just enough (might try a couple of small pry bars) that you can slip a screw driver or brake adjusting spoon inside the drum to back the shoes off that way.
If that doesn't work and assuming that the star wheels are broken off the adjusting bolts, grab the the hex part of the bolt with some vise grips and try pulling the adjusting bolt away from the backing plate. The broken part of the adjusting bolt should pull through the backing plate giving you an access hole. Then try reaching in through the access hole to back off the brake shoe.
There are a few more options if the above doesn't work, but they are a bit destructive.
When get to the point of putting the star wheel back on the adjusting bolt I can help you through that part too. But make sure you do that before you put the shoes back on.
Good luck, Paul.
