I have seen a "Change Path" button several times. I cannot recall exactly where but next time i see it i will come back to let you know.
I have never selected it, so no promises on what exactly it will accomplish for you.
The "switch path" option is only available for Series 2 Skylanders, it appears in Persephone's cabin during her upgrade dialogue. It allows them to swap between their final upgrade paths without the need to reset the figure like you had to do in the first game. This option is NOT available to any of the new skylanders (jetvac, fright rider, shroomboom, chill, pop fizz, sprocket, flashwing, or hot dog) or the giants.