If you're going to do something illegal, you can roll back your odometer without replacing the cluster. But...that would be illegal.

If you're all set on replacing the cluster, I highly suggest rolling the miles on it forward to match your current mileage.

http://webpages.charter.net/mrfatbooty/odo.htm

Disclaimer: The link above should only be used to match the mileage of a new odometer to the actual mileage of the car, never to roll back your odometer or commit fraud in any other way. That's illegal and if you do it, that's your own fault. I'm providing the link only for purposes of rolling an odometer forward.