How easy is it to retrofit cruse control and the driver information stalks, and what is involved apart from obtaining the stalks required, and could it be done without a visit to the dealer.

I have the classic and want to fit cruse control and have the driver information available, to check fuel consumption

See here

Had the dealer do mine - £162 all in. Not saying they were ham fisted but after the work (including a service) there was a problem with the main light switch and the trip computer function button on the other stalk stopped working. These was replaced under warranty so I now have two new column stalks and a light switch.