It was almost as if the zombie Frankenteddy was speaking to me asking, "Please get me off this sweater and make me a real teddy bear. I promise I won't eat your children's brains." So I obliged. Here's how you can free any other poor character out there from the confines of their ugly sweaters.
First, turn the sweater inside-out and carefully cut out both sides together. Don't handle it too much or it will start to fray.
You can hand stitch it, but I recommend doing it on the machine for less mess and faster results. Leave an opening in an inconspicuous area (I chose the inside of one of the legs), turn it right side-out, check to make sure there are no gaping holes where the machine missed, and stuff it, then hand-stitch the opening closed. McKenna helped with the stuffing part:
Much better. Now there's one less ugly sweater in the world and one more zombie teddy bear.