From Ringeck:
[27] Note the mutating [Mutieren]
Deploy the mutating thusly: When you bind him with the over-hew (or otherwise on the sword), then wind the short edge upon his sword and drive well up with the arms, and wind your sword’s blade outside above his sword and thrust him to the low openings, and this conducts to both sides.
From Pseudo-Peter von Danzig:
Here mark how one shall drive the Mutating to both sides:
Mark, when you hew strongly on him from above your right shoulder to his head, if he parries and is Soft on the sword, then Wind on your left side with your short edge on his sword, and drive up well with your arms, and drive in with your sword’s blade above over his sword, and stab into the lower opening.
Another:
Mark, when you hew to his head from above your left side, if he parries and is Soft on the sword, then drive up with your arms and hang in the point above over his sword, and stab into the lower opening. Thus you may drive the two techniques from all hews thereafter, as you fin