You will just need a coverter that goes onto the speedo cable..
your car has a manual set up for the speedo drive , and the converter sits in the middle of the cable , between the gearbox and where the cable enters the car.
Its a bit of a git to get to,but once its in, thats it. I think the converter is about £60.00 tops..
Try SVA in Dover, or EBAY ,....
Your speedo will read in MPH, but the dial will show kph...if that makes sense
good luck
jon