I know that Haasman has done the job using a floor jack.It would be best if you use a coil sping compressor to hold the spring while you disconnect the UCA. However you decide to do it, as always, be careful. Consider replacing the UCA bushings and sway bar bushings while you have the UCA out. If the UCA ball joint is bad your bushings are probably bad also, both being about the same age.
Easy job, not considering the coil spring . Release the upper ball joint from the steering spindle. unbolt the UCA from the body of the car, unbolt the sway bar, install the new UCA with new bushings and sway bar bushings ( a little silicon spray helps it go in easy), Torque to specifications, reattach the steering spindle, torque to specs and release the floor jack. Get an alignment.
The concern is the spring force while the UCA is released from the steering spindle. Your floor jack MUST not slip form the LCA or the entire force of the spring will be released. Make sure you have a good floor jack. Not a cheap flimsy one. Chain or strap the LCA to the floor jack pad. Again you don't want the LCA slipping off the jack pad.
With the coil spring compressor, you don't need to worry about this.
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car