At the moment you can't lawfully make clans at RuneScape
Just take the Level 61 Kharid Warriors and OSRS gold take them up the crate and throught the pantry. A small cutscene will happen when you will see the Master's servents pull out swords and daggers. The Master himself will soon pull out a dragon dagger. Following that, you'll have to fight your way through servents until you arrive at the master and kill him. Bring them back
Source: thefreshloaf.com