This one can be a real pain in the ass to get. When you turn the lights on and are totally prepared you should all head for the stage. Stay away from the fireworks display at the front of the stage however as it will hurt you.
If you can have one person watch the left side of the stage in the far corner, have another one in that same corner and more to the front, then have someone in the middle-ish and then have someone who can free roam here you should be okay in the stand. Tank's suck here but you can run around them as the stage is fairly big. And for an added bonus you can call up the fireworks again and quickly back off to have commons get nailed by them.
As far as when the Chopper comes, it will be on the left side up in the bleachers, you'll just need to jump in. This sounds easy, right? Its not as you get swarmed by commons, uncommons, Specials and a Tank. If you can stay mostly together then you should be alright.