I need a 3D solid from a 3D mesh model

I need someone proficient in Solidworks and/or Rhino who can convert a surface model of a boat into a solid enabling me to 3D print sections of the hull. I have various source files .obj .ma fbx and more i am not familiar with I have been working only with the .obj opening in solidworks and converting to mesh attempting to work with surfaces and profile slices to reverse engineer the original model.

Essentially I would like
- model scaled to 1.2m in length from original scale (+3m)
-hull only extracted from model for future use - everything above and including fenders to be removed.
-model origin shifted to centre-line at the stern/back deck level of hull
-solid created of the hull model
-ideally it would be great to know a workflow to be able to do this utilising Solidworks and/or Rhino I spent alot of time but as a new user really have struggled.