Hyrum tells Jane Manning James that the one who put the mark on her forehead can remove it.
Quincy Newell, Your Sister in the Gospel: The Life of Jane Manning James, a Nineteenth-Century Black Mormon (New York: Oxford University Press, 2019), 141
Therefore, let your Heart be comforted for he that changeth times and seasons and placed a mark upon your forehead, can take it off and stamp upon you his own Image, now therefore look and live; and remember the Redemption and the Resurrection of the just and it shall be well with you.