Even though this didn't solve the problem of the knocking on my vts, I thought I would make a guide for this because I couldn't find a proper one with pictures when I was looking before. It's not a particularly hard to job to do, but some bits are just fiddly. It took me about 2 hours to do both sides. Here it is in easy steps...
Axel stands (optional, but safer!)
17 and 18mm sockets
17mm deep set socket
Spanners (like a dick can't remember the sizes but around 17/18!)
WD-40 (or any other penetrating fluid)
New pinch bolts for the ball joint. Can get these from Citroen for about a pound each.
Part number for pinch bolt: 352243
Part number for self locking nut: 362230
Start off by loosening the wheel nuts, and jacking the front of the car up. You can use 2 axel stands and get the whole front up, but I decided to do one side at a time. Take off the wheel.
First off you have to loosen the nut where the ball joint is. If you're finding this difficult, spray on some penetrating fluid such as WD-40 and return in 5 or so minutes.
Then locate the bolt that goes through the bush part of the wishbone, and spray on some WD-40
Then proceed to loosen this nut off using a spanner and an 18mm socket.
Next you have to access the 2 bolts that are found in the front footwells.
First off undo this bolt here
Then remove the rubber seal strip, and loosen the metal clips that hold the carpet in place
Lift the carpet forward to reveal a black flap and lift this up. Below it you should see some foam that you need to cut through with a stanley knife. If the wishbones have been changed on your car before, this foam will already be cut.
This will reveal 2 nuts, undo these using a 17mm deep set socket.
Get back under the car and completely undo and take out the pinch bolt where the balljoint is.
Once this is out, do the same to bolt that goes through the bush. I re-used this bolt so kept all the washers and bits in a safe place.
You are now ready to reomve the wishbone. If this proves difficult, use a hammer to aid you and hit the wishbone downwards. This is probably the easiest position to do this from.
Old vs New
Now you are ready to fit the new wishbone. I found this the most fiddly part but you will get there in the end!
Offer the wishbone up, hammer the ball joint end back into the hole where it come out from, and locate the bolts on the other end through the holes in the footwell. I then put the 2 nuts on finger tight in the footwell to stop them falling through.
For the next bit you use whatever method takes your fancy, but i decided to use a jack to get the bush part of the wishbone back in place to put the bolt back through.
Once this bolt is through, tighten it up and do the same to the 2 bolts in the footwell.
Then take your new pinchbolt, as you can see the old ones a touch rusty!
To make sure the ball joint part of the new wish bone is in far enough, use a hammer , so that when you look through the hole it will be perfectly lined up ready for a bolt to go through
Tighten this bolt up and check the others just to make they are too.
And that's it, your new wishbone should then look like this
Hope you found it helpfull
I will not be held responible for any damage or incidents that occur to the car, yourself or anyone/anything else if this guide is followed.