My 2006 31D has a slide mounted dinette and the seat belt frame was held in place by two 3/8" of so carriage bolts thru the floor of the slide. The bolts were installed before the slide was installed in the coach. The bolt closest to the side wall dropped right out but the inner bolt was still inside the coach with the slide extended. I used a dremel to cut the bolf as close as possible to the floor of the slide and was able to wedge it out from under the slide.
I didn't remove the dinette but the seat belt frame limit storage in the under dinette seating position. We rarely travel with more than two but if necessary we still have belts as part of the love seat. My one big cabinet project was removing the propane stove and constructing a new cabinet with drawers. Not overly difficult but you have to think ahead on how any thing you build or buy will get thru the rather narrow doorway. My cabinet screws together like something you would buy at Ikea. The top and four sides all come a part.
Photos of the project.