Like every other side mission, this mission is played on Street. The mode is a 1 v 5 Team Deathmatch. The opposing team is winning by 12 kills, but you gain invisibility. The invisibility is similar to the Ninja's chameleon trait but stronger. Walking near enemies does not disable invisibility, but firing still does.
As a general tip, avoid getting spotted. If visible the Rehab-armed enemy will eliminate you almost instantly, killing within one or two shots. You are usually killed instantly when on the first spawn because since invisibility becomes available within a few seconds. Avoid close combat, unless you have a high level melee weapon. You can also crouch down under barriers as Snipers cannot target you when on the ground.
One easy way to finish this mission is to play as the Engineer or Mercenary with an explosive weapon. Stay in the corner and fire rockets/grenades to the snipers. You can also use your invisibility to get between group of soldiers and blow yourself up. An Elite with an DSR1 camping in the corner is also a good solution, too.
You can play as Juggernaut who has Flame Armor killstreak. Because you are invisible, your fiery shield is invisible too. Just walk near enemies and they won't notice you and will quickly be ignited. Keep in mind, however, killing with the Juggernauts weapons is risky, seeing how most of the available weapons are close range. The longer-ranged R870 and Defriender shotguns are a preferable choice .
Do note that using a Ninja with a chameleon trait will downgrade the stronger invisibility to that of a normal Chameleon trait.
Normal difficulty: Sniper Class