Best way to recalibrate speedo

Start the car and put the needles in as close a position as you can remember them to being when idling. The speedo might be a little tougher,try just putting it at 0 when idling as well.

use the instrument cluster diagnostics, set cruise control at about 50mph on the highway and place the needle on, then do the same with the tach at like 2000 rpm

btw to do it

push the mileage reset thing down
turn it on to ON, not start, ON
the gauge should sweep, let go of it, push it again to scroll through it