It is not repairable, you should replace the instrument cluster.
Replace the instrument cluster.
You would fix it by replacing the instrument cluster. The speedometer itself may not be faulty, it is more likely to be a problem with the speed sensor.
These parts are only fixed by replacement.
You need to determine if it's the speedometer itself that's faulty, or the vehicle speed sensor. If the speedometer is faulty, you'll need to replace the instrument cluster.
You can't fix it till you know what's wrong with it.
Most likely speedometer cable
There is no way to change gear ratios.
That would depend entirely on what's wrong with it.
Good luck, I've got the same issue
you have to get anew speedometer,speedy bo peep.
remove the battery terminals for a minimum of 10 minutes.
There is no fixing a broken motor mount. Replace them with a new ones.