We replaced our faded and cracked decals over the last few weekends. I started by making a trace copy of one of the decals on paper. I transferred the paper copy onto a piece of 1/8th in smooth paneling. I cut out the paneling and sanded the edges. I got new vinyl from a local sign shop, by the foot. I taped the paneling on the vinyl and cut it out with a snap off razor.
I removed the old decals with a 3m decal remover mounted in a drill. I washed the camper with dish detergent to remove wax, oil and dirt. Wipe the application area with alcohol. I Sprayed the application area with water mixed with a little soap to make applying the vinyl a little easier. It came out good for first timers. The following weekend I spent 9 hours waxing the rest of the siding.
I need to upload after pictures from the camera and post on here. It was a lot of work but my labor is free to me. We spent less than $100 for the entire project.