Co-pilot seat repairs

Hey guys!! I'm new to the board - Lead Head is the name of my 1984 V20 Steplift. Have owned it for four seasons. Have had the passenger captains seat pull out of the floor a couple of times, and have moved the round pedestal base to new locations and screwed it in again. Was told by a friend that the next step will be to repair by opening a hole in the floor and putting a ring of marine grade wood under the base to screw into from the pedestal above. I'm sure someone of you have done this in the past. Is it a huge job or is there space under the this area to work. Just want to know if I will get into a repair that will involve the immediate area or if a 2-4 foot area will be involved? Any information would be appreciated. Thanks, Lead Head