It's been a while since i owned a paintball canister....so here's my best shot at this.

If you push in the pin at the top, it will not blow up the canister. This is acctually what allows the co2 out of the canister. Do you ever watch the guys fill up your co2 canister? they put a hose on it. That hose on it has a pin that pushes the other pin (someone please correct me if i am wrong)...the co2 then travels through that hose and into the co2 canister. You want to do the opposite of that, by attaching a hose which runs into your tank, or rubbermaid, or whatever you use....screw the hose on and the co2 will leak into the hose and into the execution unit (hehe..i like that.....execution unit)

Hope this helps.