Things you need:
1. A private server with teleporters
2. A level 70 with flying trainining and mount(if your not a druid)
2b. A level 70 Druid with flying form
3. a Carved ogre idol ( Link)[Druid only!!]
What to do[druid way]:
Do not do step 1,3, or 4 if you want to look like a bird and not your self!!
1. Use the Carved Ogre Idol
2. Go into flight form next to a teleporter in Shattrath or any other place in outlands with a teleporter
3. Take the costume off while you are still in flight form
4. Use Teleporter to go to Exodar/ Silvermoon
What to do[ if your not a druid]:
1. Mount up next to any teleporter in Outlands
2. Use Teleporter to go to Silvermoon/ Exodar
Bonus:
if you have two accounts on that server or a really nice mage friend ask him to teleport you to Silvermoon/Exodar if mages can make them ( they can on my server)
If your alliance and want to go to silvermoon use the teleporter to go to Zul'Aman then fly to silvermoon