HOW BAD IS HELL? FIND OUT.

Step One:
Gather materials.
You'll need a good, sharp saw, lots of towels, and I suggest vice grips and straps to hold your leg still. You'll need a tourniquet. A belt or rope will do. A red hot iron plate for cauterization should be nearby. And, of course, you're going to want a stick, or a wallet - something to bite down on.
Step Two:
Get in the right mind set. This is going to hurt, and hurt bad. Plus, if you pass out in the middle, you're liable to bleed out and die. You're going to have to ...