When this happened to my Golf it turned out to be the motor mounting bolts working lose allowing the motor to wobble against the linkage causing the system to jam up. As the bolts loosened over time the symptoms became worse until it all seized up.
To get to the motor I needed to remove lots of equipment above and to the rear of the engine. Fortunately there was a fibre-board cooling grille above the motor so I just chopped it out and tightened up.
Amazon will sell you a Haynes maintenance manual for under £20. Spare parts can be had from your local Motor Factor - see yellow pages. My guess is though that you will probably need neither manual nor parts.
Good luck...
Peccavi
July 2009