I have no experience with 3D printing but I managed to remove the foam and export to STL by using the trial of ABViewer. Just open the file, select a foam piece and turn the layer off on the right hand side. If you're on Windows 10 you can use the included 3D Builder to make it ready for print.
agreed for intricate character design, his is pretty basic IMO. check out the .stl i created last night. when exporting to .stl it gives the model the triangular surfaces. it was solid modeled with a extruded region intersected with an arch then unioned to a sphere with the eyes and mouth subtracted. ACAD cant import the .stl but there is a free trail viewer from ABViewer