With Open Arms (10 player)

Very easy to solo at level 90, be careful not to use abilities that hit more then one target (Maul in my case) as the arms are quite squishy now.

DPS harder. We did this today - 3 healers, 1 tank, 6 dps. No in-combat resses at the kill. Freed the first two grabbed people, then just sacrificed the next ones (a healer and a dpser died). All our dpsers were hovering around 4.5k and we did this without breaking a sweat. Actually, we killed him this way just because we couldn't get a second tank :>

We completed this acheivement without freeing anyone (didn't want to risk accidentally killing the arm, it nearly died anyways due to incidental AoE in the raid).

We, luckily had two druids and a warlock in the raid; Rebirthed the first two and Soulstoned the third while he was in the grip. With an ICC geared raid, you should only see a maximum of three grips, making this an easy 10 points.