Defeat the Dancer of the Boreal Valley
Go to the Consumed King’s Garden
Defeat Oceiros, the Consumed King
Find the Path of the Dragon gesture in the area after Oceiros
Go to the Irithyll Dungeon
Reach the large open area with the dragon statues and the corpse holding the gesture
Use the Path of the Dragon gesture on the small altar near the cliff edge
Wait for the teleport to Archdragon Peak