Odometer question
 

I recently realized that the odometer on my recently purchased van is increasing too fast, at a rate of about 1/10th mile every 100 feet, but sometimes even faster. It's already increased 60000 miles since it's last documented state.

I know I have to adjust the rate at which it increases. Is there anything I can do about the miles that are on there already? Should I just roll them back by hand after I fix it, and not tell anyone?

Anyone had anything similar happen?

I ran a limited slip in my Dakota for about 10 months and the carrier did not have the speed sensor ring on it. I've got about 15,000 more miles on the truck than is shown.

I would fix it and then roll it back to the proper mileage though.

Thanks,
Would certainly be easier if the mileage stopped going up instead :D