Dorman does make replacements, and they are reasonably priced -IF- ordered online thru some parts supplier. I just bought one last week from Advance Auto Parts because of the lifetime warranty. This will be my third one (last one I bought thru ebay). I got it for 66 bucks online shipped thru them.
I did not remove the seat cover. If you look at it, you can put the new one in, under the cover, and on top of the cushion, and once positioned, remove the sticky tape, and lay it out like a decal, sticking it down, as you pull the tape cover off.