Rough country ... wouldn't go in alone unless I had to, and particularly not without letting someone know when, where, etc.
So I'm assuming you start off by reaching for a stick and tie a piece of cloth around your upper arm (or above wherever he did his hewing). Make a nice pre-tourniquet.
Let's assume about a 2-inch knife. Lowest hanging fruit first....start on top. Slit quickly through the flesh and to the bone. Try to get as deep as fast as you can. One smooth stroke with ample pressure. Hope your knife is sharp! Keep that tourniquet tight!
Now we work that blade around both sides. Then from underneath a nice clean single stroke and most of the flesh is severed.
OK. So that only leaves the skeletal connective tissue. Gotta work that blade in between a joint and separate the upper arm from the captured lower....and poof! You’re free! Gotta keep that tourniquet tight!!
Man...