Convert mph to kph

Car is a JDM and was converted to mph in the UK.
They are the kph clocks that are reading in mph. How can I convert them back?
Is it a case of removing some already fitted converter at the back of the clocks?

could it be just a new facia reading ?
remember when km came out I got a letter from Murphy & Gunn offering to convert my old car

The clock has the kph but just the K blacked out to read MH. More I'm thinking about it, there must be a converter of some sort behind the clocks to calibrate it to Mph.

maybe buy clocks take of top and fit
not sure but at a guess be same thing

Generally in the UK they fit a jdm converter as all jap import cars have to be sva tested when imported,which means they usually get the rear fog light and the converter fitted which makes them legal for UK roads.
With that in mind Alan I'm not sure what way they done it but if you took the clocks out you should see something wired in or maybe into the ecu.
Here's something like what possibly has been used

Send litchfield a mail with vin number

im sure they will advise you