It wasn't a difficult job, just awkward. I know Ben Hau can replace the unit as a service, hes on the facebook pages. end of the day its just nuts and bolts, its not cheap even doing it yourself. IIRC the column was £560 delivered.
on some videos showing the bush change they remove steering wheel but that not necessary, just drop the column down and unbolt the power steering motor. i believe if its driven with a failed steering motor bush for too long the vibrations go into the column and cause the wear. so if you hear the steering rattle get the bush checked asap, its only an £8 part.