My 01 disco has a mph cluster which is not so good in Canada. Lol. I picked up a metric one from a wrecking yard for cheap. Should it be just simple plug and play or is there more to swapping them out?

 

If you can, get the matching ECU and BCU. Otherwise you'll be stuck getting a scan tool that can mate the cluster to the computers.

Alternatively you could actually pull the clusters apart and just swap the backing cards. Not a very hard job I don't believe, and you would retain your correct mileage that way.