Here is my pet method...it sounds unorthodox but I assure you it works. It really does....
What you need is "shock" not brute force....
Hit the "side" of the spindle where the tapered hole in the spindle is..Hit it hard with a 2 or 5 pound ball peen hammer or sledge. Hit it often but hit it solidly and hard. It it from all sides as best you can. It will upset the press fit of the taper between the spindle and balljoint enough that they will literally fall apart before your amazed eyes! (and you'll feel so clever when it happens!) ::
The ball joint will just "pop" loose when it's ready..if it's not ready it won't. Keep hitting the side (hard!)
I don't reccomend pickle forks or hitting a nut threaded on the balljoint stud

. I've done both and they do work but the consequences are severe if you have a problem. Like, maybe deforming the stud with the nut in place and "then" have the joint open up but having a trapped situation where the now free ball joint has a stuck nut preventing you from removing the loose assembly (been there,...done that). Pickle forks and bad news too, the tear up the spindle as well as the balljoint (been there,..done that too!). And you have to hit them so hard that if you just spent the time and effort hitting the side of the spindle in the area of the taper as I reccomend it would come loose anyway.
Try it and be patient!
Also, another tip...spread some graphite powder (purchased from the key and lock section of your local hardware store) on the taper of your new balljoint before re-assembly. You'll be very glad you did the next time you need to remove that balljoint!
Good luck! Let us know how it works! ::