Not sure if it can be done by anyone other than Rover (or someone with the right kit).
I had a keyfob on my wifes rover reprogrammed last year , it was from a scrappy as the original had come to the end of it's usefull life! All Rover dealers have an electronic reader which I believe does more than programme the security ecu! you activate the keyfob and the programmer accepts the new code. Takes longer to open the bonnet and plug in the reader than it does to programe the new keyfob in! The question I ask is why does it need reprogramed, if you put a new battery in just follow the instructions in the handbook, or find a rover or even ex rover dealer, they will have the electronic gizmo to do it.
Des