The ball joint must be pressed into the spindle. It takes a special tool or one He** of a good press operator (I used to have one but he retired about 15 years ago - so I had to buy the tool). It is not likely that a generic ball joint tool will work as the clearances are small.
With the special puller its just a matter of disassemble and reassemble. The tierod end and the balljoint have tapered shafts so they won't just fall apart with the nuts off. Technique becomes almost as important as tools at that point.
Bosch Master, ASE Master, L1
33 years MB technician