From what I remember when I removed the steering lock on mine, take the top bottom steering column plastics off, slide off the plastic (immobiliser) ring around barrel (un clip plug first maybe?) . There's a pozi drive screw at the top (or bottom), take out. There is a catch\detent which you have to fiddle with, (push with small screw driver) to get it to retract a bit and once this is over come the barrel will slide out, undo plug now or before. Reverse for fitting.
It is a lot easier than you think and as simple as I've explained.