Step 2: Phase I - Render
1) Open your .obj character model in a 3D editing program. Personally, I use MeshLab, which is an extremely powerful, open-source freeware developed by the University of Pisa in Italy. You can get it here: http://meshlab.sourceforge.net/ Other freeware 3D programs include: Blender, Metasequoia, Wings3D, Google SketchUp, and 4Dblue. But, MeshLab is the least intimidating if you are completely new at this, like I was. If you have trouble navigating its buttons and extensive menus full of technobabble, there are a lot of helpful tutorials on YouTube for specific functions. Note: Of all seemingly basic features, MeshLab does NOT have an undo function. So, don't mess up this next step!
2) Delete all unwanted parts of the model. Assuming that it is a human figure, 'unwanted parts' would include everything from the neck down, and his or her neck, face and usually ears. If the ears are pointy, super long, or unnaturally positioned, like cat or bunny ears, feel free to leave them, of course! If the character's hairline is visible, then oftentimes the upper polygons of the forehead will show a little bit of the hair creeping onto them. It is tempting to delete these since they're mostly skin, but DON'T! You will see why, later. Other than that, delete everything that is skin or clothing, but leave hairpieces like bows, beads, feathers, etc. Only delete hats if there are hair polygons underneath them----do NOT delete a hat if doing so would leave a big hole on top of the model.
3) Export as a new .obj
....CONTINUE TO NEXT PHASE!