Use a ball joint separator or a pitmann arm puller.

 

Both Jason and Kai have the idea on breaking the taper on the lower ball Joint. I steer clear of the traditional "pickle-Fork" as it may damage the lower ball joint dust boot. It is better in the given situation of "clicking" to change the whole shaft and is considered "Gravy" as Jason can attest. The only time I re-boot is if there is no "clicking" and the boot has minor crack in it with out any break in the integrity of the boot. If the boot is already broken you can re-boot it with a kit (not recommended) and can be gaurenteed a return visit. "Be sure to stake your axle nuts"