Basically what you want to do here is kill ten Cerberus Guardians through the little slots of their shields. This isn't as hard to do as you might think it is and on almost every play through I've done, I easily kill ten Guardians through the little slots.
What you need is either a good sniper rifle or mod another gun of your choice with a scope. A gun with a high accuracy rating is prefered.
Just try to stay out of the way and don't get swarmed by enemies. Having an ability like Drone, or taking a character like Edi (with her Decoy) will help keep enemies of you.