Back in 1976, I lost a very good friend to shop stupidity. He was changing brakes on a mercury, with nothing more than a bumper jack. The jack slipped an the spinol came down on the inseam of his leg and he bleed to death in less than an hour!
Please remember that you can DIE if your not careful. ALWAYS use proper equipment. suport your vehicle with the proper jack stands for the weight of the vehicle you are working on.
Just my $.02 keep it fun!