How do I promote someone to be leader?

Hello, I'm a guild leader, we are raiding, though not very far in yet. I'm very unlucky, because my internet will be going off for a few months in a few days. I don't want to just leave my guild behind, is their anyway I can promote someone else to leader?

Thanks in advance.


edit: lol, my avatar still says I'm 49. I'm 60, it's messed up.