http://www.icy-veins.com/wow/iron-reaver-strategy-guide-normal-heroic
[video=youtube;ncLWElLJgqM]https://www.youtube.com/watch?v=ncLWElLJgqM[/video]
When the Iron Reaver marks you for Artillery (http://ptr.wowhead.com/spell=182108/artillery), move away from other raid members before the Reaver finishes locking on. This attack deals damage to the raid based on how close they are to the effected tank. This is the tank swap.
When the boss is in the air:
Don’t worry about getting targeted for Artillery (http://ptr.wowhead.com/spell=182108/artillery), that will be cast on damage dealers for this phase.
Kill bombs.
Ground phase:
Barrage (http://ptr.wowhead.com/spell=185284/barrage), a cone attack in a random direction.
Blitz (http://ptr.wowhead.com/spell=179889/blitz), a charge in a random direction and then back to tanks.