Get hold of RAVE and follow the procedure in there. Its a seat out job and you need a bit of room to work to get the covers off to see the elements. I did my drivers side recently, and the main problem that I haven't yet resolved is the cushion cover is held on with a long clip strip sown into the cover - this broke in removing the cover so the cushion is now loose. The cushion material on the door side of the seat had collapsed as well and half the material came off with the element, so I plan to replace this with an Exmoor trim cushion.
Covers are originally held on with hog rings - my local indie specialist recommends cable ties to replace them.
Lastly, you need to replace both elements as a pair (cost just over £100) as the design has changed and you can't mix and match them.. The new ones are a diffferent shape as well - they don't go over the side bolsters which is where mine had blown. Obviously that was a weakness.
Cheers!
Graham
