I am on level 4 of Halo 3. I've beaten the 1st two parts, killed the brutes, taken the ghost, brought down the scarib and got ontop/inside. When I get on it the general keeps saying "Find the weak spot, take it out at the power core, you'll know it when you see it". Where in hell do I shoot it??? I've thrown grenades all over that beast and cant figure out how to kill it to finish the damn level.