Step 1: Have most of the Jackass crew think they are doing a photo shoot for the upcoming movie. Schedule the shoot in a tear gas chamber that is dressed to look like a photo set. Have secret film cameras planted in the chamber so you don't have any obvious camera men walking around with gas masks on inside the room.
Step 2: Make sure the room is secure so nobody can escape. I would have the supposed photographer excuse himself from the room because he brought the wrong type of memory card or whatever before you lock down the room.
Step 3: Let the tear gas rip and watch all of the crew cry and scream in pain as their eyes get dominated by the tear gas. They will probably try to break out of the room, but it will only add to the hilarity since these chambers are rock solid.
Step 4: Make sure to research first how long these guys can stay in the room without collapsing and dying...oh whatever, these jackass guys are tough, right? LOL
I think this prank has the perfect combo of epic and suitable for broadcast TV. Thanks for reading.
P.S. that's quite a snot hanging from the army dude's nose. Just a little taste of the gross and agony you will see in this prank.