Blender File that needs to be setup for Makerbot 3D printer

Hello all,
I have a blender file that I need 3d printed. It needs to be separated into 3 different parts before i can print on a 5x5 platform. I am having the most difficult time slicing the model. Any suggestions or help?

Thanks
Dana

Try to use this method.

http://www.blender.org/manual/modeling/meshes/editing/subdividing/bisect.html