Tips on replacing upper ball joint on 99 2500 4x4

while replacing the front brakes today i noticed the left upper ball joint is bad.do i have to pull the rotor first then what?? undo upper and lower ball joint nuts and beat out the joints. i was going to do both while i had the yoke out.any help would be great. thanks.is there a easy way to get the rotors off?i would like to turn them.