First step disconnect the power from the lines.
Then you can clean and wrap that area of the wire that has some damage to the insulation using vinyl electrical
Put that area of the RV on your list of annual cleaning chores
It is not all that difficult of a job to learn how to install good quality electrical
crimps on wire. You do need a special pair of pliers for it but they are not expensive. The crimps are color coated by wire size but they work on a range of sizes. Just go to a neighborhood type of hardware store. The clerks there will sort you out with the right tools and fittings and if you go on a slow day they may be able to give you a DIY lesson right there in the store
But if not just head to youtube where there will be dozens of online tutorials showing how to use the tool to install crimp on connectors.
Making good wire connections would be an excellent subject for hands-on lessons at the various FGRV rallies. You don't need to teach the full on electrical systems, just little stuff like this is valuable knowledge that is not overwhelming to teach as a quick lesson.
Quite easy to do, don't be afraid to try. Get some extra crimps and scrap wire to practice with. Much less expensive to get some practice materials and tools than having a mobile RV service pay a house call
Plus then you will be ready to handle these minor electrical situations in your vehicles.