I want to rescue the NCR troopers without killing any of the Legion, who are currently neutral towards me. I find that it's impossible to reverse pickpocket weapons onto the troopers, so I tried just dropping the weapons in front of them, hoping that they'd arm themselves to aid their escape. Just 'cause I though it'd be a hoot, I even dropped the Avenger in front of one trooper. Unfortunately, these troopers must be green, because only once have they picked up the weapons (and they almost made it, but instead of shooting their way to the door, they hung around too long. Most of the time, it's the legionarries who pick up Avenger (that's fun, too, but not what I want)

Has anyone had any success with helping them to escape? Remember, I don't want to kill any Legion for the moment.

Sniper Rifle with a silencer is my only advice.

I've got an EW build. No silent kills for me.

If you can't do silent very well, then go for extra noisy. C-4 reverse pickpocketed or dropped next to each guard (can't remember how close the last ones are to the prisoners, you should be far enough from them), then stealth around a corner out of sight of everyone and hit the detonator. As long as you were not detected when you hit the button, and there are no survivors, it will count as stealth kills.