Here is a quick guide on how to upgrade your Legendaries to item level 970 in Patch 7.2.5!
Once the Tomb of Sargeras is unlocked you should visit the Blacksmith in Dalaran to pick up the quest Unsettled Power.
Just as before, you will need to collect 50 Essences of Aman’thul.
Essences of Aman’thul Sources
- Tomb of Sargeras Raid Bosses (per-boss basis, will drop on all difficulties!)
- Weekly Mythic Keystone Cache (20!)
- Emissary Bags (3-5)
- PvP Weekly Quest
Once you have collected 50 Essences you can hand in the quest in Dalaran and you will be rewarded a Stabilized Titan Essence. The quest is repeatable for every Legendary you have.