How to customize wordpress theme

Hi,

I am using attitude theme for my website. while looking on web i found intersting menu effect here
http://tympanus.net/codrops/2013/04/25/simple-youtube-menu-effect/

Can anybody help me here, how do i add it my theme. Source code is avaiable but i dont know how do i use this?

Sorry my question might sound silly.

Thank you.