Well, at least you know how to get to that point right before the valve. Two things tho, that guy on the video checked if there was any air left on the system by making a few dry shots, not recomended at all. If you shoot the rifle with no air behind the valve you can damage it since there is no resistance on the other side and the valve may over travel, to make it safe i'd do what Ernest did on the minute 5:03 on this video.
Just open the valve manually.
And the second thing. Shoot Chuck a message on this forum, i'm sure he's gonna be glad to help you out and he know's more about streamlines than me.
https://www.airgunnation.com/members/chuck/ And once again, let me know if you have any further questions.
Manuel