The linkage is famous for wearing out, do you have trouble getting 1st & 2nd? It is quite an easy job if you are good with your hands. At the gearbox, from under the bonnet, disconnect the linkage by removing the pin, which has a spring type clip that you press in and leaver the pin out upwards. You will also see a black plastic cap which is designed to use instead of a nut, and you will probably need to break this to get it of. From underneath the car, remove the linkage clamp (torx type bolt, the nut is welded so you won't need a spanner), then separate the linkage and prize it of the part where you removed the black plastic cap. All will become evident when you have the new part in your hands. Get a friend to help line up the gearstick by selecting 1st at the gearbox, and 1st from inside the car, then tighten the torx clamp. A lot of trial and error here. Hope this helps.
Dode, December 2005