Originally posted by Tevirik:

You have to go to your spawn area where there are 5 or 6 erected stones.
In your inventory, you put the trophy in one of the quick access slot, for instance 1.
When you are in front of Eikthyr's erected stone, you press 1 to hang it.

After that, you have to press "F" key to activate your power.

It just keeps marking the location if I press E, or if I try to quick slot with it it says it's not compatible.