This is old and was posted a long time ago.
Also please note that IF your raid starts combat the trick is MUCh less likley to work, its better if the raid runs into the hut just to the right & behind the scout who runs away. This way there is less chance the warriors that spawn run to the raid after the person vanishes.
This can be done using a Rogue's vanish or a hunters feign death.
The hunter/rogue must actually hit the warriors before he vanishes/feigns otherwise once again there is a good chance the adds will run straight past them and aggro the raid (messing it up)
Also note, if you mess it up, run back towards the instance entrance, the mobs will drop chase after a while giving you a chance to do it again.
ALSO note this desawns the bird & warriors AND the miniboss at the top AS WELL as stopping anything from respawning 1h later.