To change the ball joints on a W124 with removeable joints you can do one of two things, undo the entire front end, remove lower arm (requires specific mercedes benz plate type spring compressor - I know people will tell tales of their ustaads using a jack etc. Horse crap, my life is worth more) OR buy the MB jig to replace them in place.
I made my own press for cheap and replaced them easily. This press is made with 1/2 inch thick steel plate with 1/2 inch thick grade 8 threaded rod and grade 8 nuts. When cranked this press can apply gargantuan force.
At first I removed the brake caliper with carrier, ABS sensor, disc, hub with strut and shield to get to the effing rusted pinch bolt of the joint. I used aerokroil some heat, a drift and a 2 kg hammer to knock it out once I undid the nut with a 3 ft breaker bar. Be sure to use a jackstand under the control arm otherwise your family would be having the local masjid announcing the time of your namaz-e-janaza. That spring WILL KILL YOU if it lets go of the arm.
After removal of the hub and strut- here is the rusted 18 year old joint in place (car has a build date of 1994 Nov)
Here is my self made press installed for removal.
Here is the hole the joint sits in
Here is the worn out joint (it had about 2 or 3mm up and down play in it) :o
Here is the new genuine lemforder joint installed with the same press - You need to align a notch to the centreline of the arm to install correct otherwise the joint wont swing properly as the working hole on top is oval
The entire job in actual time took about 3 hours but in those 3 I had to tend to my daughter, attend my phone, have lunch etc etc. So in real time I think 1.5 hours.
my car drives like a new car again. TIGHT, SOLID and composed even at 100 mph