plz let us know how it goes and the method you use, I've been looking at this for a while but havent taken the leap as my rear UCA is fine knock on wood
You would replace as a unit. You won't save almost any money trying to press-in the balljoints and bushings and you WILL collapse the arm before you can do that. Trust me, I tried. I got 1 bushing almost all the way out before it started to collapse and after that I said F this and got a whole unit. MAYBE if you got it super hot with a torch and had access to a press you could get it out, but it's not a DIY-able project with rental hand tools.
I just replaced my 2 year 5k mile lifetime warranty Movotech supreme UCA last night. I
think I trashed it while my rear diff was locked on pavement and I stupidly was doing figure 8's trying to get it to unlock. The ball joint was rock solid and showed no signs of wear, though the pinch bolt and ball joint sleeve was starting to corrode. Biggest issue is that both bushings were soft and the left side one had started to tear (which is what makes me suspect I prematurely trashed it). I'm going to say that the MEvotech supreme one is okay, but is probably won't last a lifetime. Good news, RA will just keep sending you new ones.