Not to a Honda but have replaced digital speedo, odometer unit to a KTM Duke. Really easy just disconnect the battery first. Remove headlamp to expose wiring then it was just one multi plug connector which only goes in one way. A couple of screws to undo then job done.

Ordered direct from KTM dealer, who supplied one with the correct mileage displayed. No checks made, just told them the mileage over the phone so could have stated any mileage but hey I'm honest !