I think phines had to replace one... they are expensive.. somwhere around 500-1000 installed I think. Someone would have to verify this. I don't think it would be impossible to do yourself... it would probably take a while, but someone here carries and extra in his off-road gear, and I would think he expects to change it on the trail if he's bringing it along, so it can't be impossible to do yourself....

just re-read your post... sorry, it's just the boot, but the install time is probably close, and I'm not sure you can just buy the boot either.