Following on from the previous post about the ankle grip, this short clip covers removing the grip.
Make sure that you lower your weight by squatting and not leaning over.
Reach down outside the leg and grip the lower edge of the hand, right by the little finger.
Curl the hand upwards, don't pull. It is a manipulation of the hand not a strength move.
Don't release the hand until you have started the pass and broken the structure of the guard otherwise they will just re-grip.
Remember, think 'curl' not 'pull'.
Let me know if it works for you.