For the RC51 I think the only way to change maps is to use a Power Commander. With some other bikes you can send your ECU off to various places that can 'flash' the ECU, i.e. change settings and the map(s).
Once you have a Power Commander, you can do it yourself. You connect the Power Commander to your computer and then send a new map to the Power Commander, and the Power Commander knows to then use that one.