It's not a modification I've considered, but I did have the bed mostly deconstructed while I worked on some other projects/problems.
You will not be able to re-use much of the bed structure for what you are planning. The bed is supported by blocks fiberglassed in around the edge, then with 3 beams spanning the width (that is, running trailer-front to trailer-back). Those 3 beams are in line with the front edge of the kitchen cabinet, down the center, and in line with the front of the fridge wall. You might be able to re-use the outer two of the beams, but I suspect they aren't in an ideal location (too close together to define the front edges of the benches).
The floor under then bed is finished, and it's already raised (to fit the fresh water tank underneath it), so you should be good to go there. You will need to be careful if you put any screws down through the floor not to puncture the fresh water tank.
Finishing the structure shouldn't be too tough if you have any experience with wood working. If not, it still shouldn't be difficult but you will need to do some learning.
2013 Escape 19 ("The Dog House") , 2012 Nissan Frontier