As with all techs it is a comprehensive understand of what is happening that will unlock any difficulties. You must take it past the embryonic stake in order to comprehend. Analyze dont memorize EP.
This tech and what can be learned from it is valuable.
Step in right neutral bow and poke to the eyes this momentarily cancels height (up) and depth, as the fingers make contact with the eyes allow your elbows to bend as you simultaneously drop your height anchor your elbows to rip down opponents arms, this action will reverse the height cancellation thus pinning his feet to the floor and bringing his head forward ultimately maintaining his position.
During this anchoring action let you right shoulder drop into his chest placing your head on his right side and tucking, thus fusing your bodies (This body fusion is extremely important if you are to maintain contact manipulation and causative creative control).
As you grab the testicles take a miniature shuffle forward as you pull your elbows slightly back and up (Dont exaggerate this motion it doesnt take much to get the desired effect) maintaining body fusion, your opponent may now raise on his toes his height cancellation being reversed upward again.
You will now find it simple to deliver the reverse backnuckles to the kidneys (getting the desired nerve response) as you have the required depth penetration as a result of the body fusion.
The reverse backnuckles hook inward keeping your opponent in position, because he is pinned against your body he will not be able to resist the penetration, as they pass through his ribs bring your fist up your centre line you should feel your forearms contour his chest as you come in thumbs to the eyes (the elbows should shoot outward creating open ended triangles as you deliver the thumbs. This is more for structural enhancement than blocking as you will find that his hands will raise to protect the eyes after the thumb pokes).
You are now in a position to rip down again as you anchor the elbows pulling a straight line only until your elbows are at your ribs (economize your motion) before you circle the backnuckles into the temple strike.
Grab the head and again anchor the elbows, dont pull the head in order to get the knee shot, pulling the head has a tendency to spread the elbows and disengage your core mass as such reducing stability and impact value.
Hope this helps.
Best in Kenpo