Hi, Mike,
Not sure if the wiper switch on the stalk can be repaired.
The stalk itself is not difficult to change: you can unscrew the switch from the steering column and the 2 horn wires, but you have to remove the wires from the 12 (?) pin plug as the plug will not pull thru the steering column tube. Make a note of all the colours and where they go. Not easy to mess up as they are all cut to length.
Price of the stalk is a different matter!!
naj