Remove the upper and lower steering wheel cowls.
The upper cowl is secured by two screws on the front of the assembly which can be accessed by rotating the steering wheel to the 3.00 and then the 9.00 positions
The lower cowl is attached by 3 screws from below.
Now, insert the key and rotate it until it is in the I position.
Now insert a small allen key as shown below into the small hole in the steering lock assembly and remove the lock barrel.
When re-fitting, if the steering lock bolt snaps in (steering lock will be on) push locking stone downwards using a screwdriver until the retaining bolt snaps in
Now re-fit the lock assembly
Note: The following requires care!
With the lock assembly removed, it is now possible with great care (keep the key in the lock assembly) to dissassemble the lock mechanism (beware of small springs!) to remove, clean and then lube the 10 or so plungers.
It is also possible to adjust the plunger profiles using a fine file with the key fitted to overcome sticking ignition locks.