I just watched this video, and in about 5 minutes I got the achievement. I've been trying for 2 days too. BTW I had it set to "Difficulty 1, and 5 Lives"

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Xbox Ambassador

*Laser Enthusiast*

Thanks, gonna give it a whirl tonight.

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1000 Point Club
Assassin's Creed
Avatar TLAB
Bully
COD2
COD4
COD W@W

How can you do it? I've tried shooting a narrow passage and I always get derezzed.

Just passed it. It's really tougher than I expected but I got it.