As Scott has mentioned Bodsys Brake Bible is one of the best sources for all things brake related.
While it is a bit of work to remove the rear disks and give the park brake a clean, adjusting it only requires the removal of the rear wheels and a flat blade screwdriver. Takes about 10mins each side, including removal and replacement of wheel.
If you dont have the little rubber grommet that covers the adjuster hole, dust and muck can get in and if thats the case I'd recommend cleaning it properly.
I bought a couple of grommets from repco for about $5 and they do the job nicely. I forget the size but i think its 6 or 8mm (or maybe 1/4").
Ive had the EPB module jam before. It's a pain to release, I'd recommend adjusting it ASAP :)

