Adjust the auto adjusters to the minimum point where the shoes are just about to touch the drum, fit the drum back on, then stamp on the brake pedal a few times, providing that the adjusters are working it will set itselt up.
After doing this, make sure that the back wheels are not binding with the brakes off, and all will be okay.
I had to change the adjusters on my Clio last year and they were bl**dy expensive, but an easy job to do.
Sally-Ann, September 2005