speedo/odometer calibration

I was wondering if anyone knows how or can recommend someone for speedometer calibration and odometer reseting?
I got a new cluster for my 89 mustang (finally getting rid of that 85). I want the mileage set true and while im at it id like to ensure that its properly calibrated before i install it in my car. Any recommendations appreciated, thanks!
 
If all you need is the odometer reset, remove the speedo from the cluster, take a small punch and hammer and tap the pin out from the center of the odometer #'s, turn them to face your desired mileage, and drive the pin back in. Pretty simple really, I've done it on 4 85-140 speedo swaps. Or send it to me, and I'll do it and ship it back as long as you pay the freight...