I completed this yesterday on Insanity, and it wasn't too hard: I did it on my first try.
Class: Soldier
Map: Wingman
Squad: Javik; Grunt
Shepard: M-7 Lancer V, with AR Piercing Mod IV and AR Magazine Upgrade V; Cerberus Nightmare Armour.
Javik: Particle Rifle V, with AR Stability Damper V; AR Piercing Mod IV.
Grunt: M-7 Lancer V, with AR Stability Damper V; AR Piercing Mod IV.
Strategy: Play smart. I don't think I did anything particularly clever. Stick to cover as best as you can, and go from cover to cover when the grenades are thrown at you. Keep distance between you and the enemies, and use the terrain to your advantage for breaking their line-of-sight. As with the rest of Insanity in ME3, and so too on lower difficulties, make use of your squad powers - Grunt's Concussive Shot is very useful for setting off Fire Explosions, primed by Shepard's Incendiary Ammo, and Javik's Biotic abilities keep the enemies debuffed.
I found the fight at the end of the DLC to be harder, for comparison. Grunt and Javik were particularly useful because they actually engaged the enemy, unlike some squadmates that just seem to stand around.
I'm happy to try my best to answer any questions, if there's further details you feel you may need.