I have done this, complete removal strip down and rebuild with new polybushes from the states, new nuts and bolts the lot, i had to literally cut the lower control arms off, sheared off a couple of welded nuts and had a bloody hard time stripping it down, took me a good few days with just the subframe on the garage floor carfully cutting with a dremel and angle grinder to get the parts off. I then went and purchased cheap lower arms but realised that they were missing vital plates for strength and the bracketry for the xenon headlamp level adjuster sensor so i had to get plates welded. I wont lie it was a right PITA, i needed a 12ton press too so bought one of these. If you buy new control arms get them from ford if you have Xenon headlamps as i have not seen a cheap set that is correct, same for the front control arms one of these too has to be right for a ST170 with Xenons.
You have been warned lol
I have loads of pictures of my restoration i can post.