use jack and 12mm dia long bolt or 1/2 inch socket extension to press up disc in bottom of arm remove circlip if tight tap ends of circlip inwards to free it first ,remove spring ball joint etc clean arm and you need to make a puller out of 12mm flange bolt or similar ground to fit through top of arm but big enough to catch ball joint seat and wind out with nut and big washer on bottom this is hardest part ,new seat will tap up with suitable socket,it isnt much easier with arm off vehicle,as it is at least held firm while working on it ,apart from pullers which on their own wont remove stubborn arm hitting arm where it goes around sector shaft will allways get them off but large hammer and drift like halfshaft is required to stretch and so release taper joint,same principle as for removing track rod ends where you hit end of arm not joint and joint pops out undamaged,i do them too regulary
