Rogue Trooper Redux

I achieved about 90% of the required kills on mission 3: Nort Naval Base.

Upon leaving the starting area and entering the building, you're getting the task to "Disable the elevator with a micro-mine to prevent backup from arriving". This is in the same exact area in which you're getting the tutorial that Gunnar can be used as a turret.

Take out all enemies in the area, but do not disable the elevator. Instead, position yourself left of the elevator, take a few steps back, wait for the elevator to arrive and for two enemies to step out. Upon exiting the elevator, those enemies will turn left (away from you) , and they're not going to see you if you're positioned correctly. Now, immediately sneak up - while crouched - on the enemy that is closer to you and hit to perform a kill-move. If done properly, the second enemy didn't notice anything and you can do the same with him.

As long as you don't place a mine on the elevator controls, those two enemies are going to keep respawning. Just get back into position, wait for the elevator to arrive, kill the enemies, rinse and repeat.

Don't worry if you're accidentally disabling the elevator instead of performing a kill-move. There's a checkpoint right at the beginning of the area and the kills are accumulative.