Flash a v3m to generic?

I have a verizon v3m phone and I want to flash it to the generic motorola UI or the alltel UI. I am experienced with seems and ect..., but I have never flashed. the only reason I want to do this is because I want to have an animated wallpaper to put on it. Is it true that when you flash you have to reactivate the phone with *228? if so, please explain to me if the reactivation will go on my bill and how much it will cost me.