Or manually... any figure, useful for posed figure props for instance

File:Import:Wavefront OBJ... all options unchecked

File:Export:Wavefront OBJ...

File:Import:Wavefront OBJ. All options unchecked EXCEPT Weld Identical Vertices. Final prop.

UVs will be maintained. Usemtl groups maintained (It's not necessary to check Preserve Existing Material Names)

The resulting prop will have no poly groups, the prior existing body part groups have been dumped. A single group is easily added by either opening the OBJ in a text editor and adding g NAME directly before the facet (f) blocks (usually the g will be in place but must be named as desired)...

Also note that the winding order has been altered, caveat.

Or if you're sqeamish about editing OBJ files just use the Group Editor

New Group...

Add All