If you replace those ball joints AutoZone loans the tools out for nothing. They push in and out easy. Getting the spindle off the old joint you either need a tool to go in between the upper and lower studs and push the bottom one out or you can make it with 3, 1/2 or so bolts and a couple of barrel nuts. Take one of the bolts and cut the head off and thread on the two barrel nuts and put the other bolts on the end and you have a tool to do the same thing as the one in the shop manual for about $2. Or, if you watch a suspension tech, he'll take a big hammer and smack the side of the spindle and it will pop right off!
If it was me I would take a real close look at those ball joints before I repalced them. A lot of GM lower ball joints have wear indicators on them and are easy to check. A lot are replaced for no good reason IMHO.
If the grease boot is busted then it's your call.
If you have something loose out at the wheel I would look at the wheel bearings to. They are known to get play in them @ 100k miles.
JS