He will live on through the gifts that he gave us with his talent. Take the strength that he has given you and use it to make Chester proud by living each day helping others. Help lift people up when they fall down.
This is operating under the pretense that Chester 'left'. In reality, he's still here. As Hybrid said, he lives on through the kindness you bestow onto others, and through anything you do that is done with the intent of helping people around you. That's the way we ensure Chester never goes away.
Bro his music will live forever. Seriously. I use to listen to metal in junior high and then got into rap but now I'm going back to rock. In fact, I was listening to some Silverchair just a few days ago. Real music lives forever. So will Linkin Park.