there is no way that i know to make a 9 volt a 12 volt. BUT...i do know how to make a 9 volt an 18 volt (faster than 12 volt). Take the 9 volt rev, and take out the battery tray (it has the metal things for the batterie, etc.) Take a 12 volt battery tray and put it in the 9 volt. (in other words switch them) Then unscrew the 9 volt paddle (there is a screw keeping it in place in the middle of the pddle) and switch it with the 12 volt paddle. So basically, switch the battery trays and switch the paddles. The 18 volt mod is FAST, however, it blows boards faster than usual.
"You and I have the courage to say to our enemies there is a price we will not pay, there is a point beyond they must not advance.. You and I have a rendezvous with destiny, we'll preserve for our children, this the last best hope of man on earth or we'll sentence them to take the last step into a thousand years of darkness."
- Ronald Reagan