Help in MGS4 spoiler maybe

hey im sneaking through the game without killing anything im at the part on act 4 where the gekko hitches a ride on the elevator and i have to distract it for 3 min while the mark III opens the door.

how do i do this without an alert??

I was just there.... I died 4 times using the rocket launcher, grenade launcher, etc...

then i used slugs from the m4 shotgun attachment and shot the satilite 3 times and it died right away without even jumping off the ledge... i dont think it even alerted... then again maybe it did..