The quest, The Fall of Taunka'le Village
,
makes you escort some tauren. Abadon it. In a random time interval, a damned spirit will spawn. This spirit gives xp when you kill him. So just go afk in a hut with a macro simular to:
/target damned
/cast mind flay
and use a automouse clicker or a little korean to press 1, where the macro is, constintly.