right then, lets get started
this is a gearbox
but it ain't got the cradle on it, because thats here
remember though, all this has got to be done underneath the car if you haven't already removed it so it'll look a little something like this
for the sake of ease in the pics, the gearstick does not get removed from the little bit you cant to change until the end, but you will need to remove it before you get the box out, or indeed, before you undo the cradle as there will be nothing to stop the shaft from moving when you try to get the pin out
right then, so you've undone the 4 bolts and now you need to get the rest of it in bits, here is where you start

you need to poke these little bits of rubber off to get the dust cover off, haven't got a dust cover? why not? it's there to stop all the shit from gettign into the joint, as well as keeping it nice and clean with grease etc, so make sure you've got one to put back on, otherwise you will have to go through all of this all over again
so, you've got the cover off and now you can see this

this is the pin that holds the bottom of the balljoint (which is attached to the gearstick) to the selector (which is in turn attached to the gearbox via another set of pins)
what you need to do is to undo the locking tab washer so you can undo the nut (13mm), don't worry about it turning, it won't
and it won't becaues the other end of the pin looks a little osmething like this
then comes the task of getting the pin out, which will need some careful taping because it's normally covered in a bit of crap
here are all the bits once they have been taken apart, notice that there is a hole in the side of the selector rod in which the locking washer slots in, when putting it back together again, htis is possibly the hardest part to get right due to the limited amount of space available
no goback into the car to get a view of this

ok, so it's a bit blurry, but you should be able to see a circlip in there somewhere
remove this clip like so
there is also a washer in the way, but we'll get to that later
once this is done, get back underneath the car and get hammering at the bottom of the cradle to get the plastic carrier out of the base of the cradle, use a block of wood or something so you don't bend the bottom of the shifter mechanism (if you are replacing it you really needn't worry about bending it, but just in case things go tits up, it's worth taking the precaution)
you should end up with something a little like this

notice the washer dangling in the stick
if you haven't removed the top of the gearstick, now is the time, and then you end up with something a bit like this
all you need to do now is find yourself a big vice and, to be perfectly honest, you would also benifit from a 27mm 3/4 drive socket
put the socket on the top of the stick (remember you should be able to see one edge of the plastic a series of spreadable bits of plastic which is the end that will expand NOT the other way around, so push the expandable bit over the ball)
now you can replace the original ball joint thing you have, with the new quickshift bit of kit you've boguht fomr somewhere
put it all back together again in reverse order
along the way i have made a few mental notes as to what the best course of action is if you are under the car, and the best way is probably to remove the prop so you can attempt to slide the whole cradle over the end and get it out into the open
you obviously need to remove the gearbox crossmember and the rear prop mount to enable you to get the gearbox down enough to get access, but just remember that the exhaust might get in the way as well
any questions?