I want you to go to 4-B-1 in the book and mimic the picture, with one exception. I want you to point your thumbs straight out and away from you when doing this. Now, bend ONLY your right elbow. This should make the right thumb point skyward. Finally, without bending the left elbow, make the left wrist cock so that the thumbs match the direction they're pointing. This is a demonstration of the text found at the bottom of the page in 7-3 (the bending and straightening of the right elbow cocking and uncocking the left wrist). Therefore, the #1 accumulator uncocks the left wrist. I, personally, have no awareness of the #2 pressure point being active other than its orginal pressure established in the grip.
The idea that the Cocking Right Elbow Cocks and Uncocks the Hitter's Left Wrist is tough for many to grasp. The same is true of the fact that the Right Wrist only Bends (Horizontal Grip Motion 4-0/4-A) and does not Cock or Uncock (Vertical Wrist Motion 4-0/4-B). Luke's exercise is a 'must' for those players wishing to understand these radically unconventional -- but dynamically correct -- concepts.
Do it first as Luke suggested -- Hands apart per Photo 4-B-1 -- and then Hands together, with the Left Hand Thumb being gripped with the last two fingers of the Right Hand.