Hi,
probably the resitor pack on the fan motor,
maybe lube the clutch linkages, and also try that for the lock barrell,
chaep and easy stuff 1st..!!,
Charlie
pup the plastic plug out of the middle of the wiper arm, remove the nut, remove wiper arms, remove large nuts underneath, then remove 2 I think nuts holding the motor to the bracket, then remove the whole unit.