I just did this on the weekend.
AMS is must. #1 proirty absorbs 100% FP and the dot (the pally loved me saving 9% of his mana for this) #2 is IBF sufficent to absorb dmg. #3 is UA and dodge trinket (UA absorbs some of it) but it really hurts should you get FP & hit at the same time. #4 AMS. #5 parry trinket if IBF not cooled down, #6 parry trinket\IBF (dependant on #5), #7 AMS.
Hopefully by now you have downed steelbreaker. If not plan for overheals. for the next couple of FP.
But agree on Acclimation for this fight. When it was stacking it reduced the dmg nicely