Water tank replacement on 95 2300sc

I had a cracked water tank on my 2300sc and decided this year it would be nice to have use of the sink and transom shower. I found access panel in cabin which is next to porti pot. It look like an easy unbolt and install job. I called local Maxum dealer and purchased replacement tank. Unfortunatly I did not try to remove old tank first. Now I can't get the tank out. I opened access door and there is not enough room to get tank out and under. Has anyone had this problem or know how you can get this tank out and replace without cutting the deck.