Not sure if the arrangement is the same but on our 99 Marquis, the commode is on a 4" (or so) elevated platform and it was real easy to remove the tile, sub-flooring on the pedestal and then using 2X4's and a piece of good quality 3/4" plywood, build a new platform butted up against the flange for the toilet. I then cut to fit under the toilet a piece of 1/4" siding to match the tiles.
The main issue I found was that the original pedestal had no real support around or near the flange and with the original Sealand china toilet and it's frequent leaking lower seal ruined the cheap material used. After rebuilding the sub-floor, I replaced the Sealand with a China bowl Thetford and have never had to deal with leaking seels since.
Not a lot of effort ... taking one afternoon's work a couple years back