Bookpedia- rename custom column

[bosslisa]

Hi, I'm a Bookpedia noob & was unable to find help with my query- probably because it's very obvious... :/
But I'd appreciate if someone could tell me how to rename the custom columns. Thanks!

[Conor]

In the program preferences (you will find it under the Bookpedia menu) under the first tab General, the ten fields at the bottom.