I can't, for the life of me find the video, so here are the Traxxas big bore shock cap mod in pictures. Sorry.
I used these mini vise grip pliers to hold the cap while I cut the hoop off on a band saw.
This is after the cut and next is a cleaned up cap.
Here you can see the difference.
To find the center of the cap, look to the inside, there is a dimple which is like a center punch mark. It really helps in finding the dead center of the cap. Then you will use a 5/32", 4 mm or use a # 22 drill bit to drill a hole in the cap. When your done drilling this is what the cap should look like with the 4mm button head screw.
http://a4.ec-images.myspacecdn.com/images02/152/d8bb3b9105c848fc9dc66b0ad7b621ac/l.jpg
After this is complete, all you have to do is seal the screw with silicon grease to prevent leaking and then thread on a Revo rod end.
This is the end result.
Oh, don't forget the diaphragm in the cap.
Next it the complete shock assembly.
And there you have it, if done correctly, you will have a modified Traxxas big bore shock cap that won't leak.
Good luck and I hope this works for you."thumbsup"