Well, story so far...
Got the 2nd hand one from leavevalleymotors.co.uk, tried to cancel but it was already on its way, so anyway it arrives, I fit it, (You were all right, it was a piece of cake) Took it to the Vauxhall Dealer who enabled it, however it did not work

turns out leavevalleymotors.co.uk sent me one for a diesel, so I bought a new one from the dealer for £35 and took it home, stripped down the cowling, took out the diesel stalk, opened up the box for the new one, and surprise surprise it was a indicator stalk without cruise control, I'm sure there is a lesson there about checking parts before starting work, anyway. Rebuilt the steering column and took it back, after 5 minute argument with parts department who insisted it was the correct part for my model "IT IS THE RIGHT PART BUT I DONT WANT THAT PART, I WANT THIS PART INSTEAD! I WANT TO GIVE YOU MONEY FOR THIS PART" he eventually conceded and orderded the part in, due on Friday.
So, I have to agree, it would be a piece of cake, but sods law seems to working overtime with this one.