Place axle bar into a vise and tighten vice so that axle does not move.
Remove clamps from damaged or torn boot.
Remove boot by cutting in half.
Position the Axle so that the outer joint is horizontal with the axle bar.
Hit the lip of the joint, knocking the joint off of the axle bar. (This may require several strong blows to the joint to get it off.) Continue to strike joint until it releases off of axle bar.
Clean inside of joint of any debris and remove all grease, dirt, etc...
Installation:
Place new boot on axle bar and slide back onto middle of the axle bar.
Replace circlip, if needed on end of axle bar.
Squeeze grease pack into joint and place joint onto axle bar.
With a brass hammer, strike joint back onto axle bar. (place your axle nut on backwards on the outer joint so that you do not ruin your threads)