I got the fork bellows from Bella corse. They are called Factory style fork gaiters and they where only $19.99. The only thing I didn't care for though is that they fit a bit loosley around the bottom portion. I just put a piece of rubber electricians tape around the fork seal area and they fit great. You get what you pay for. I'm happy. To me the stock plastic covers were water catchers, so I couldn't wait to replace them.
As far as replacing them it was very easy. Remove the front wheel, two or three bolts, the front fender, then loosen up one side of the triple tree bolts,(one side at a time of coarse). Slide the one side of the fork assembly out of the triple tree, knock the plastic guards off the slider with the edge of a piece of wood, slide the new gaiter on with clamp and put back together. Do the other side the same way AFTER you retighten the triple tree bolts. It goes without saying you have to have some way of jacking up the front of the bike safely. Wala! wbarnier