yes, i know there are many posts re: ball joint r/r, but when it came time to do it, i found many conflicting posts over the years, so i'm writing this to state clearly what worked, just a summary, not the detailed procedure -- this applied to my 81 240d, probably applies to any w123
first, we are just doing the ball joints, so the spring is not going to be removed -- therefore the lower control arm should be supported as a safety measure before removing the steering knuckle
ok, caliper hung out of the way, hub off, support lower control arm, upper ball joint is freed by the "hammer-dolly" trick(striking from opposite sides simultaneously) -- this has the advantage of not destroying the upper bj boot, so if you're real lazy, that bj will not get replaced -- lower bj is difficult access for the h-d trick, had to use a pickle fork with the tips ground off, to separate bj from lower control arm
removing the bj from the steering knuckle easy knock out -- pressing in new one: used the harbor freight tool(big c clamp), modified, see photos -- also, you remove the boot and then the small hf adapter in the kit should just fit, resting on the shoulder of the bj where the ring secured the previously removed boot -- i had to slightly enlarge mine -- which brings up another point:
http://www.peachparts.com/shopforum/diesel-discussion/275392-ball-joints-differances-tolerances-123-a.html -- there is variance in the dimensions on the bjs, one of mine was .3mm smaller than the other, not ok for a press fit
oops, edit: forgot, i wouldn't want to do this procedure without an impact wrench, high-torque -- broke down and finally bought one from hf, electric, $85 w/coupon, supposedly 1000 ft-lbs, but lets say at least 500 -- nice tool
thats all, the rest is in the other posts -- was an easy job