Need some advice please

I have Monroe gas inserts, do these replace the Piston. rebound tube stop, cylinder, foot valve and seals, or do I have to re install some of these items.

Or do the inserts just fit into the tube assembly and then held in place by the locking nut. Refit springs strut tops.

In regards to ball joints, are they a press fit (if so will need to have done in a workshop), or can they be done off axle stands