Onan carb replacement

[FarPoint]

I just bought a 1997 Tiffin 28 on a P30 chassis. It hasn't run for a couple of years, so has numerous issues. Just finished replacing siezed rear callers / pads.  Lots more issues will turn up. I'm sure.
454 seems to run ok, gen set turns over but won't start. Smells like bad gas. Dumped a bunch of high octane in the tank along with Sea Foam so hopefully the 454 will drink it.
I ordered a new carb for the Onan and it arrived looking good - was fairly impressed as it is inexpensive. And imported.
Thought I had it nailed.
Not So!
How are supposed to get that carb off? OMG AND IT's right there in front of me as I sit on the ground but I can't see o r feel the inboard securing bolt
Guess I gotta drop the genny on th ground.
Still gonna be a PITA.
ONAN 4 BGE
Any tips appreciated.
Heading outside now to have a fresh look

[Eyez Open]

Have you pulled the genset out of the bay? That has to happen to work on it; those old Onans do need some maintenance after all the years in service.

[FarPoint]

Yep. Looks like that's gonna be the only solution.
An oil and filter change, fuel filter change, and one of the two spark plugs is about all I can access without dropping it out.