It would help to have bit more specific question that "hey, how do you kill them, thx". It's not like there are some massive changes from normal, except for *way* more raid damage in first phase, and potentially raid wiping super nuke in second/third phase.
- decide how you deal with the first phase. It's possible to just ignore the adds entirely and heal through the damage they do, but it gets very dangerous during the last minute. Use tiger on the first red spin, squeeze in as much extra damage as possible and see how if you can outheal everything. If not, reveal some adds during one or two spins.
Also, if you combat res someone during that phase, remember that adds will be spamming that person like crazy for the first few seconds. It's almost impossible to survive without a big personal cooldown or quick reaction from healers.
- for fire phase, there's nothing new other than Inferno. The big issue here is the beginning, sometimes you only get a single comet and have to use it to reduce stacks on boss, while surviving Inferno without reduction. Trying to preserve this comet for AOE will only result in boss killing you off with 20+ stacks shortly afterwards. Best to leave one of statues for that moment, either healing or +hp one. Things like "don't melt a comet" are obvious - if you do that, you'll be overwhelmed by the raid damage.
- third phase is simple. Tidal -> Barrage -> Inferno -> Barrage -> Tidal -> ... Biggest issue here is proper positioning, so you don't kill yourself with a chained Barrage after a big special or accidentally melt a comet and die to Blazing Radiance shortly afterwards.
Admitedly, I haven't tried this post patch yet, but I imagine that healer cd buffs made Blazing Radiance/Inferno far less dangerous, so it should mostly be about surviving first phase and proper positioning during 2nd and 3rd.
Should use the cranes for the first tear of the sun while tanking both bosses in the center of the room so they both get hit. Save tiger for day phase so that you can survive the inferno without a 2nd comet. (always use the 1st comet to reduce stacks on boss)