Change the value of variable of an actor instance via editor

I am trying to create doors which can be opened with keys. To do this I want to give a door a name.

The door with the name stronghold can be opened by key_stronghold. The door secret_garden can be openened by key_secret_garden.

So far no problem, but how can a level designer use my blueprint easily? Setting the name of each actor instances via the level blueprint is not very user friendly. Can you change the value of a variable of an actor instance from the editor? Just click on the stronghold door, and change variable name to stronghold?

Bildschirmfoto vom 2016-08-30 21-23-41.png

Solution in german boardsür-türen-actor-instances/