cv joint issue????

my 02 AWD astro decided this morning to start shaking as if I had a loose wheel this morning when I got on the highway. Wobbled home and ended up taking the other truck to get to work. When I got home from work, I checked the van and found the right side cv joint has a slight amount of looseness to it, so I am planning on replacing the joint. Couldn't find anything else. The guy at the part store told me that many people change the complete assembly rather than just the u-joint in the boot.

Should I just replace the joint and boot or should I replace the whole assembly with shaft? Either way, how difficult is it to do and do I need to pull off the wheel assembly from the ball joints?

The steering knuckle will have to be released from one end or the other. I've found the upper ball joint is easier. Fortunately, the torsion bar is a lot easier to deal with than a coil spring. The wheel, hub nut, caliper, and ABS sensor will have to be removed and held up out of the way. It may be easier to remove the outer tie rod end as well since the steel tube housing the half-shaft will allow only a little movement of the shaft to clear out the end, so the knuckle will have to be moved well out of the way.

You can replace just the CV joint assembly. They include a new boot and usually a warranty.

checked my cv joints as per my local mechanic buddy and found no looseness, checked all bushings and u-joints and still nothing out of the ordinary. I did notice one of the calipers was a little loose, could that cause the vibration? I took it out again this afternoon and it only starts to shake when it hits about 90 kilometers per hour (55 mph). It also sounds like a brake rotor was out of round, not a bearing noise. And when I tap the breaks it seems to go away. Could a brake caliper or rotor cause this vibration issue? Where else could I look?