Fox Squirrel Reposition|General Taxidermy Discussion|Forum|Taxidermy Talk

If it was me, I wouldn’t try it if the mount is important to you. It would be easier to mount another squirrel. If you really want to do it, then I would rehydrate the arms and shoulders. I would cut the skin around the shoulder so it looks like you are removing the sleeves of a shirt to make a vest. I would cut the form arms and shoulders off with the arm skin attached to the removed parts. I would roll the skin down on the arms like a sock down to the wrist. I would alter the arms and shoulder area into the configuration you want, using wire run through the foam legs,  glue them onto the form roll the “sleeves” up and glue the skin at the seam. Or you can remove the forms arms down to the wrist and make a wire armature and use apoxie putty to build the arms up allowing total freedom of posing. By the time you are done, you could have mounted another squirrel and you wouldn’t have a seam to deal with. 

Having said that, if the squirrel isn’t important to you and you accept that it may not work out, it would be great practice for future endeavors.