This may sound crazy but it worked for me
If you have access to torches, remove all related suspension arms/components to get to the ball joint and remove all retainers etc.
Heat the ring that holds the ball joint up till its good and hot and take a big hammer and a few good whacks and it came right out.
This is the crazy part...
I put my new ball joints in the freezer the day before.... grab your frozen new ball joint out of the freezer heat the empty ball joint-less ring up again and tap the new one in when it cools its as tight as can be and I haven't had any problems so far and its been 2 years and 20,000 miles later
Just a suggestion