This now outdated plugin (Wes wrote a new Unimesh Plugin) was Wes' first plugin for Milkshape. It doesn't support fat/pregnancy and sometimes creates messy hem shadows. Each point has only one bone assignment each, resulting in odd looking animation now and again. This was primarily used to edit hair and accessories, not recommended for body meshes.
You must use Milkshape to use this tool. It supports one bone assignment per point. You can add and delete points on your mesh. This does not support fit/fat/preg morphs. The normals on these meshes sometimes seem to bleed up onto the hems of garments, and the workaround is to add more points to the mesh and try to move the shadowed sections back below the hem. Because the bone assignments are one bone to a point, the animation is not identical to Maxis produced meshes. You must weld the boundaries to smooth over the seams in the mesh. This tool is used more for hair and accessories than for bodies