The only way I can think of artificially adding miles to the odometer is to put the bike on a treadmill overnight or maybe setup a magnetic pendulum next to the speedo sensor.
Unless you can hack the electronic speedometer memory I don't think you can fiddle the odometer or engine hour clock up or down. Odometers are typically designed to be somewhat tamper proof.
I had to preset a mecanical odometer from 2000 to 6000 km once.(because I imported the bike and when you import a bike to the Netherlands with more than 6000 km you pay less tax..)
I did mine with a 24 Volt motor connected with a piece of hose.Took me 2 days continue.Odometer only went upto 110 km/h.
Was worth the waiting,saved me a lot of money!
The black and decker just stayed there to kill vibrations.