When the battle starts, use the Flechette's alternate fire. The little electric drones will follow him around the room. Also they will keep his shield down, and, if you use more then one set of the drones, as an added bonus, they will take out all the little buddies the General calls to help. Then while the drones are out there hit him with the alternate fire of the shotgun, and set electro-mines around where he appears at. The drones will follow him no matter what, so it won't be to hard to follow his movements. Doing this the General will go down fast.