Reseting thermoking TS-500 service hour meter with thermoguard control unit

[mick08n]

hi all,
any help would be apreciated, i have a ts500 unit that needs the hour meter reset to get rid of alarm 71. the fridge unit was serviced but the meter wasn't reset, im having no luck in getting answers but hopefully someone will know the solution.

regards,
Mick A

[Robert Hilton]

Is it a HMI or an older MP T? A photo would be useful.