In order to add or remove list values from your custom work attribute, start by accessing the Admin Center located in the toolbar on the lefthand side of the TreeKeeper main screen. If you would like more information on the different tools and functions in the Admin Center, please visit this page.
You will find Work Attribute List Management at the bottom of the left panel in the Admin Center:
Then, after you have found your Attribute Name, simply select the Edit button under the Actions column in the above view. This will bring you to the Modify Work Attribute List Values screen:
From this view you are able to:
Edit existing list values (be careful, this will change the value everywhere it is being used in existing work records)
Delete list values that are not being used
Add a new list value using the green plus button at the bottom of the screen