Well, as the title says.
You need a passenger mount - Mammoth, maybe even a motorcycle(not sure - havent tried!)
What you do is Invite a random to your group, ****** spamming trade, asking where you got your mount, asking for gold/whatever. Whoever you want.
You need to be in Ironforge -Ask them to jump on your mount and proceed to the forge (Where the Gryphon Master is), The two lava pools on each side.
With everyone mounted, jump in.
Once you land, dismount - Everyone but you will disconnect. They will not be able to get their character back until they ticket a GM to move them.