Video guide!
0:00 Revenant Bell Collar Location
1:27 Necropants Location
During the main quest The Animancy Method, we need to visit Elia at her Revenant Farm in the southern part of Emerald Stair.
Before speaking to her, search the revenant corpse in front of her for Blighted Crop, then speak to Elia and give her the Blighted Crop. The conversation will turn to Silvo, another one of her Revenants, but before agreeing to take care of it, choose the fourth option Where do all of these corpses come from anyway. This will lead directly into offering our body for after we die which will pop the Retirement Plan achievement. But we aren’t done yet.
After following the objective to deal with Silvo return to Elia and finish the conversation. At the end she will give us the Revenant Bell Collar as a down payment for our future corpse.
Then we want to travel to the Tago’s Tower Beacon near Shark’s Teeth in Shatterscarp. From the beacon we can head north to some ruins, climb up and use three lock picks to open the chest here. Inside will be the Necropants. Now just wear both the Necropants armor and the Revenant Bell Collar amulet at the same time to pop the achievement!