I removed the center seat section but you shouldn't have to. Remove the bolts that secure the top to the floor. You can see them in the picture just to the left and right of the removed floor. Remove the bolts in the front section of the center seat base. Lift the seat bases up on each side a place a wedge to keep them up just to the side of the floor piece to be removed. All of this is to allow you to pry the center floor section up from the front. Remove the two screws in the floor towards the front. Then just pry the front up and pull the floor section towards the front of the boat. It slides out from under the REAR center section. Mine was a real pain as it was a tight fit. Good luck!
99 MariStar 230 Sport LTR 330