I do not know how that happend (Insulation melted) or perhaps I do. but I'll not speculate
How hard it is depends on the RV.. Mine it is not easy but it is possible.
Howeer my recommendation depends on the location of the Winegard Selector seitch/power supply or (if you have a sensar pro) 2nd pre-amp
Ohk the 1st amp is in the antennak the standard wall plate is just the power supply and a switch.
I'd run new wire from there (the switch) to any handy point .. not necessarly the original connection point. and then cap off the original.