Promote New GuildMaster
 

I've checked on the blizzard site at the forums and have had no luck.

How do you promote a guildie to Guild Master if they want to take over the position?

The current GuildLeader is the only one that can promote another in his place.

Your one other option if the current GuildLeader is MIA for too long (I think if he hasn't logged on for one month)
is to petition a GameMaster (through a ticket) and they'll promote another player.

Yes, Dridzt, but this cannot be done through the guild interface.

There's a slash command for it, though I always forget... Hubby just passed on GM to someone else a couple weeks ago and he can't remember either... When you get them as far as you can promote them, try /gpromote name

Found it: http://www.wowwiki.com/List_of_Slash...Guild_Commands

/gleader name

Funnily enough I did that for convenience when Guild Banks were introduced.
(I promoted the officer in charge of banks who had most the bank chars in his account to GL to make the transfer easier)

I did it from the popup in Guild Tab of Social panel. (gui way)
When he tried to pass it back, the option wasn't available for my name (but it was for some of the other officers)

After a bit of hilarity.. with people passing the GL seat back and forth trying to get it back to me,
we had to look up and do it from the command-line like you said.

Looks more like a bug, than a deliberate UI choice.

PS. Sorry for the derailment, thanks for the addition. :)

Thank you Seerah, you always seem to come through.

Guess that's why you are a moderator now. Congrats, by the way:)