Current set up likely has one Air Conditioner hooked to a 20 amp breaker on the Generator, It may also be able to get fed via a "Front/Rear" switch inside the coach.
Mod is as follows.
Generator---------------Air conditioner (current)
Generator-----Outlet Plug----- Air conditioner
Optionally Plug--Breaker---Air conditioner
The outlet and plug are in a compartment or access panel where you can get at them from outside
You unplug from the outlet,, And plug into a HEAVY DUTY (At least 12ga) extension cord to the 20 amp outlet on the park post.
NOTE: Some parks,, can't do that.