It requires almost no coordination beyond not doing stupid stuff like punting it towards the raid. As long as someone in the frost patch knocks it away at the right time you shouldn't have problems with it.
You continuously knock it back until it gets too close and then that person kites it away whereby you knock it off them when safe and then rinse and repeat until you kill it. Its pretty much how you handle any number of meteors in P4. Is that really all you were asking? Its not hard, its just coordinating that with everyone dropping their stacks and not blowing up the breadth of frost that all gets a little hectic at the start of that phase.
Person with fixate moves out.
People inside knock the boulder as soon as flames appear on it.
Kite boulder into first frost patch when the 2nd patch appears.
Kill boulder.
Move to 2nd patch.
Go from a stacked position on Star, to force a meteor spawn in the middle, have your druid use Stampeding Roar, and split into two groups of 5. One Healer on each side (For Knockbacks) with both tanks / casters on right, and melee + hunters on the left. For my kill, we have a Resto Shaman go left to Blue, and a Holy Paladin to go to Green. Have the Healers knockback the meteors between the two groups. When you get Ragnaros to circa 10%, (Usually for it's at around 8 or 9%) have whoever is currently targeted to run up the back where the entrance is, and chill out there with the meteor.
Then
As Yilar has said :
Person with fixate moves out.
People inside knock the boulder as soon as flames appear on it.
Kite boulder into first frost patch when the 2nd patch appears.
Kill boulder.
Move to 2nd patch.
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