I don't have a video but photos 12 and 13 in the set below kind of give the ideahttps://picasaweb.google.com/116304768940029889451/HokSila2012?authuser=0&authkey=Gv1sRgCMu3l8zTtoueHA&feat=directlink
Basically you tie a rope to the dolphin striker. End that isn't tied to dolphin striker gets connected to righting bag. Throw rope and bag over the hull that's out of the water. Fill bag with water. Lean back, holding rope (aka righting line) and bag should lift out of water effectively adding to your righting weight.
Lastly Murrays sells a block (pulley) system that makes it much easier to effectively shorten the righting line once you get the bag out of the water and to help you lift it to your shoulder level (links below). I use this system, then have a small loop in the righting line where I can hook my harness into and I can basically lean back hands free and let the boat come out of the water.