Remove engine compartment seal (this should simply pull off), Remove the windscreen wiper arms, unscrew the plastic water deflector.
This will access the linkage mechanism which can now be detached from the wiper motor. You should now be able to move the wipers easily by hand. If not then the linkage is seized. Most likely this is due to moisture ingress at the spindles. Remove the complete linkage mechanism and motor assembly from the car. Remove the circlips from the splined ends where the wiper arms were mounted, remove the washers and o-rings. You should now be able, by twisting and pulling, to remove the spindles from their bushings for cleaning and greasing. Re-assemble and then fit the assembly to the car with linkage and motor in the same positions as when dismantled. If unsure then with the assembly in the car but with the linkage still detached from the motor, switch on the ignition and give the wipers one sweep. The wipers of course won't move but the motor should now be in the parked position. Switch off the ignition. The motor cover has a position marked for the final link parking position. Re-fit the water deflector and the wiper arms at their parked position on the windscreen. re-fit engine compartment seal. Everything should now be back to normal.
Hunter, November 2007