Check it the same as you would u-joints.
Lock the hub, get the front end off the ground. Any turning of the shaft should produce the exact same rotation in the wheel. Slop means worn joints. I just replaced mine, made things a lot better.
Not too bad. If you're gonna do it, have a die for a 14X1.5mm. It took me two days to do it, but only because I boogered up the threads on the ball joints, measured them as a 13, and couldn't find a die. lol, measure twice, run around town once. Other than that, it's just separating the ball joints past removing the brake rotors.
Get the shafts without the inboard cups... replacing the inboard cups is a PITA.
viewtopic.php?f=24&t=21561that might help too.