I had a problem getting into my 306 drums and the best source of info I found on the net was downloading a 205 Workshop manual from http://www.acrobatfiles.com/peugeot/212-8306-pdf.html It was really hard sliding the drum (with bearings) off the stub, but I got there with a puller I made. Once inside revealed it looked very much like the pictures in the 205 manual and I did some work on the brake cylinder without difficulty.
Simon
October 2007