Need much help with a Montana 3750FL

[Phlypp]

Does anyone have the time and patience to help? My ex-wife died of cancer two years ago and her three daughters inherited her Montana 3750FL RV. One is in the Army stationed at Ft Leavenworth; another has been sick for two years and is awaiting surgery; and the third is perusing a master’s degree while working full time and raising a family. They’ve asked me to do something with the RV so it can be sold.

I’m in northern Virginia and the RV is stored 2 hours away around Lake Anna, VA. My goal is to be able to start the RV enough to take pictures, clean it out and move it up to northern VA for sale. I find the Keystone Owner’s Manual too generic to be much help and many videos are focused on the features rather than operation. For openers, I don’t even know how to start it. It’s in a grass lot with no power or water and has been winterized but not moved for two years. Reading various things, it sounds like there are different switches which could be turned off or on. I haven’t found the battery and don’t know what to do with the generator. Anyone willing to assist?