firts I would like to say that I was NOT the one found out about the thunderbrew enlarge trick,credit goes to the person originally posted it.
Ok,you need to be an Alliance and obtain [Tree Diguise Kit]
Get a Warlock,and one person with multi passanger mount,and another person to assist summoning the stone
get to Traitor Cove where you can use the kit,use [Thunderbrew's Hard Ale]
Drink until you reach maximum size, (every brew give you 3 stack) maximum size is 30 stack.
Tell your friend to summon you,have the person with mount wait at the stone mount up
once summon is lit up,use the kit,accept the summon to get to Dalaran and jump on the mount asap.
???
Profit
Video: