Rotate the grind adjuster until the stop-screw in the first pic is near the switch pointed to by the yellow arrow. This helps the upper-burr-holder threads pickup at the correct spot.

Set the upper-burr-holder in place with the slots matching the illustration in the first photo.

CRITICAL: Study the second photo. While pressing down with one hand, begin to rotate the grind adjuster in the direction shown by the arrow.

Continue rotating the adjuster until the upper-burr-holder is all the way down. The stop-screw should be about where it is in the 3rd pic at this point.