A newb on a bike forum posted this pic of his hand. He was oiling the chain with the bike on a stand while running, and put it in gear while holding the chain...... not a good idea. One trip around the rear sprocket is all it takes to remove your finger tips. He took the pic while waiting for the ambulance.
I agree with Back. only pussies wait for ambulances. Badasses wrap that shit up with their sock and create a tourniquet. Drive your ass to the hospital and fill the shit out with your left hand. It may look like a retard wrote it but who cares. Your a badass it wont matter.
I'd take my bike to a dealer or a service center before attempting something I am no trained or educated to do instead of manning up to the job, my ego will be untouched. I assure you!