This is an EPAK version. I am looking at a low line knife attack, which can easily be changed into a high line.
When executed in Long Form 6, the left downward outward parry/block is simultaneous (if it does not replace) the "right vertical outward block to inside of opponent's left punch" as noted below. As you counter grab the opponent's weapon hand with your left (rolling it such that if the opponent does retain the blade, the arteries are not exposed); Then insert a inward horizontal middle knuckle strike to the inside of the elbow. If the opponent does not release the weapon, continue to control the weapon as you execute the right hammerfist, obscure elbow and claw, handsword, and kick - NOTE: you can do them all without releasing the weapon hand.
Not my favorite technique against a knife, but this is one way that I have seen demonstrated
16. UNFURLING CRANE (front left and right punch with opponent's right leg forward)
1. While standing naturally step back with your left foot into a right neutral bow (shift your hands into guarding position), deliver a right vertical outward block to inside of opponent's left punch.
2. Immediately shuffle in and execute a right inward and left outward combination on the inside of opponent's right punch, continuing the right inward and transforming it into a right inverted downward hammer fist strike to opponent's groin. (Left hand checks).
3. Follow up with a left inward overhead claw and right rolling vertical back knuckle thrust to opponent's face.
4. Dragging your left foot to your right, strike down to opponent's groin with a right rolling inverted downward hammer fist. (Left hand checks).
5. While close (shuffle in if necessary) in to your opponent, strike up and to his jaw with your right elbow (obscure wing fashion) continuing the move and transforming it into an inverted upward five-finger claw to opponent's face.
6. In the same move deliver a left heel palm strike (fingers pointing inward to your right) to opponent's solar plexus and a right front scoop kick to opponent's groin. At this point your right hand is raised and cocked above your head and you should be balancing on your left leg in a one legged stance with your right foot cocked.
7. Simultaneously deliver a right inward hammering handsword to opponent's neck and a right knife-edge kick to inside of opponent's right knee.
8. Right front the kick go into a right front crossover and cover out twice toward 6:00.
Just some ideas,
-Michael