Is there a way to "Re-Update" my existing account on my Xbox One to be concurrent with my Xbox 360. For example, my Xbox 360 account is at level 86, and my Xbox One account is only at 60, can I somehow update it, by uninstalling the game or something along those lines? Help.
No, you can not.
While you can transfer your character from Xbox 360 to Xbox One, you are making a copy of the character, and converting it to the newer console. From this point on, the Xbox One character is completely differant to the character on Xbox 360.
You also can not transfer your save back to the 360, as this feature was provided to allow players to upgrade consoles without worry about starting over, and does not support going in the opposite direction.