You need the wireloom, which is where probably Jan got stuck as they are no longer available from the dealer. Only if you can get an X3 loom and modify.
You need the satnav computer as well (about £100 - £200 depending on your luck on finding one).
Was going to do this many years ago but decided it was a project to far at the time- so glad I didn't now as I like the clean look of the screen less dash more now as the satnav seems old fashioned IMHO.