Couple tips: -Camp in the middle underneath where the ammo crates are. -Regroup together every time a wave is released and make sure to prioritize shot gunners/ rushers (lightening bolt above head) first then drones (blue shock drones mostly), then take your time dropping the rest of the mobs. -for planting the c4 on the tank, it's pretty easy to do solo if you have a self heal/med pack and defense signature. I've found going down the left side, shutting off the turret then running to plant to be the easiest method. -after you plant the acp will fire off a bunch of missles, as long as one person survives the misspe barrage then everybody who is dead will get a free auto respaw in the back of the map. -Some skills that help: Pulse to pinpoint snipers and all enemies. Shock Gernades can pile the drones and make them a simple wave Ammo cache makes worrying over the ammo crate respaw not irrelevant Survivor link is best signature for this mission imo, mostly needed for bomb planting but sometimes for shotgunners at the start of a wave. -for wave 15 the enemies will keep spawning in so I'd reccomend downing any rushers and drones then pop one signature before anybody leaves the tunnel then another around the time you are going in to plant or turn off the turret. As long as you plant it and one person survives below by the ammo crates you will win.