How To Kill The Boss In Halls Of Eternal Frost

Up until the Acheron Endboss the instance is really easy. But the Boss and its minions are really tough.

One Player needs to collect the sand from the desk. Make sure it is not the healer and not the (main) tank.

Clear the room around the boss. Now, the player with the sand can trigger the fight by talking to the boss. he is going to spawn minions. The player with the sand will always have initial aggro. He now runs out of the room and through the corridor. He/she takes the corridor, that leads back to the boss room at the other side. The player with the sand is able to run in circles and drag the minions after him.

The tank shoots the boss after the pull and drags him to the rear end of the room, where he is killed by the group.

This way the sand bearer can pass through the boss room without losing the minions.

When the boss is dead, the minions will disappear, so no need to kill them. They do massive damage and have a lot of hp anyways.