I did it 2 days ago on my resto sham, 905 equipped. Between 20-30 attempts, according to my Nethershards count. Getting the grasp of P1 was the hardest, and all became easier as soon as I planned my CDs in advance for waves 4-5. Same thing with the Raising Army phase, I failed that once before correctly planning for the 3 waves (HTT/Asc+BL/End of BL was enough to heal all but 1 ghost).
This is what I did for P1 wave 4:
Stun 1st dance, Astral Shift+spam self heal for 1st fixate, HTT second dance, earthbind 2nd fixate+spam self heal, stun 3rd dance then you should be down to 1 soldier and damage is low enough. Always keep the mage on focus: interrupt every other Blast, Purge when you can't.
For wave 5:
BL start, Stun asap to catch all 3 before Sting/Dance. Asc 1st Sting, SLT second Sting. Mage should be down then (control him like wave 4). Stay on your toes for Stings and it should be good.