Put the minions faction symbol forward (button in the back) and when you launch it, it will convert. Pity it ends up upside-down on the floor after ejection.
Compared it with the original WFC version. Very similar mold with the exception of the chest gimmick. Robot mode is both off in both versions. Chest too big for the FoC ver and the shoulders too large on the WfC ver.
Vehicle mode too boxy for the FoC ver and edged out a bit by the WfC more flat look and better grille/teeth.