1. You and your team should buy as many heavy ammo synth packs as you can.
2. Have everybody concentrate the same leg with their heavy weapon.
3. Everybody go crazy on the brain when it's exposed with their heavy weapon.
4. Syth some heavy weapon ammo when you run out.
5. Repeat.

If anybody has a strat to do it faster, let me know. Otherwise, this and the orb boss are really really tedious. Don't even try without a heavy weapon and at least a few syth packs.