You niggas is Nutso, I take off your roof
Nutso was a character in the film Above The Rim who fell off a roof and died as he was trying to tap backboard.
2Pac was a protagonist in Above The Rim, as well as Juice (mentioned in the previous line). Nutso is slang for crazy and roof is slang for head, so Game will shoot your head off if you start acting crazy.
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