How to get the cowbell skull on halo 3?

[Ggfb]

Whenever I go to the place it is supposed to be, it isn't there.. And I am on normal difficulty. Please help because it is the last skull I need for the hayabusa helmet.

 

[Next Hines Ward!]

This one is a little tricky! Here is the website on how to get it. Good luck!

 

[Sublimeonelove]

Try you tube.