you can take the outter joint off, with no issues. I actually did not even remove my boots, so I cleaned the joint, still on the car.
I did boots on a friends car, put the axle in a vise, BETWEEN 2 PIECES OF WOOD, so you do not damage the shaft, then at the outter joint, put another small piece of wood there, and give it a solid whack with a good sized hammer, it usually comes right off. If it does not, rotate the axle in the vise, then try at a different part of the joint.