This is notated quite simply with the move of the Mission followed by the follied piece in brackets. For example, as a very first move of a game, we could write, Mh3 (N).
A piece may not be follied if it has already made its first move, or if the adjacent Mission has already vacated.
To perform a Folly, first make a regular move with your Mission, and then in the same turn, place either the adjacent Knight or the adjacent Bishop onto the home square of the Mission, now vacated.