My lower left balljoint boot is split pretty good and leaking grease.

1.Does the balljoint have to be replaced or is there an alternative?

2.Can I just replace the one balljoint or do they need to be replaced as a
pair (one side) or even a set (both sides)?

3. Is this a sign that the balljoints are going, or that the other boots will
soon split?

4. I'm guessing I need to take it to a shop to have it done bcause it needs
to be pressed out and in. True?

5.Ballpark figure on what a shop might charge for replacing a balljoint here
in SoCal of where ever?

Any advice appreciated.
Thanks
Jeff
83.5 Westy
LA,CA