From Halopedia, the Halo wiki
The song's title uses 'leet speak' and is derived from "love your friends".
The song was originally titled "Ki11UrFR3NZ", but Greg was forced to change the name when Xbox said they would not publish or promote a song with a title that is spoken as "kill your friends".
It runs for 2:18 and the lyrics focus on the multiplayer of Halo 3.
Call your friends and bring a gun
Bring...a...drink or three prepare for war
The true elite
Time...flies...by the time we realize
In the end
Kill your friends!