Several years ago I removed the YSE12 engine and installed a 3GMD, increased the horseppower from 12 to 20. I wanted more access to the engine compartment than I had through the hole in the quarter berth area.
The forward bulkhead is installed with screws, remove the cushions and then start by removing the outboard panel and work your way to the bulkhead. The berth area is essentially gutted. I then removed the inboard bulkhead by cutting it about 2" up from the floor of the berth with a circular saw. Part of the bulkhead needs to be cut with a hand saw, it's not easy but can be done. Watch for installations on the inside of the bulkhead and plan ahead. I spliced the bulhkhead back in with a plywood splice plate.
I willl go to the boat today to take pictures and try to post them here.