Raiding Party achievement in Destiny

Just play through the raid as normal but before starting make sure you all join the same clan on bungie.net

*Everyone playing must be in the clan at the time you kill Atheon/Crota*

After you have joined the clan, a button will appear that will allow you to set the clan as your xbox clan, everyone in your fireteam must do this for the achievement to pop.

NOTE: With many achievements in this game, it may not pop immediately, e.g; my achievement popped the day after I actually completed the raid