Have the same problem on my BN1...I have a Mike Lempert wheel installed, previous owner had it set up in the "Y" position, when I flipped it to the correct position it is off about 10 degrees now.
For me, fixing this involves:
1) Disconnecting turn signal wires at the front of the car, requires removal of the left wheel to remove the grill.
2) Disconnecting the stator tube at the olive at the gearbox, letting steering fluid leak out and make a mess
3) Pulling the trafficator/stator tube assembly/turn signal wires all the way out of the steering column at the wheel side
4) Taping some twine to the wires so I can pull them all back down.
5) Removing Mike's wheel from the hub by removing the 9 small screws
6) Un-torquing the large Whitworth nut attaching the hub to the steering column(for which I cannot find an appropriate socket - going to try a 38mm socket...)
7) Turning the hub 10 degrees
8) Re-torque the large Whitworth nut - which is now probably stripped because I used a metric socket
9) Re-istalling the wheel and 9 screws
10) Pulling the turn signal wires back down, and probably having the taped twine come away from the wires lodging them halfway in the steering column
11) Yell at my wife and kids for no reason, other than the fact that I am frustrated
12) Re-terminate the turn signal connections because they have been broken off by being manhandled through the column.
13) Re-tighten the olive
14) Refill steering box
Any wonder that I've been avoiding this job for six months!