Begins at thrall in the blasted lands
All the way south in winterspring in the frostwhisper gorge, on the north side of the hills there are spikes, follow them all the way to the right until you reach a dwarf
Talk to the dwarf and melee her when she becomes attackable so that you can get the "On fire" debuff which lasts 2 minutes. Ranged attacks and spells do not work.
Fly north until you reach a cave which is east of everlook (NOT the winterfall village one with the furbolgs)
Inside the cave she is in the north part of it, talk to her and melt the ice. You can't melt the ice if you don't have the "on fire" debuff
Part 2 is next