Delete Custom Field
1 - Click into the Client Admin Center .
2 - Click on System.
3 - Click on Business Rules in the dropdown.
4 - Click on the Custom Fields tab.
5 - Under Custom Fields on the left side of the screen, click on the Custom Field you want to delete.
6 - Click on Delete Custom Field.
7 - You will be asked if you are sure you want to delete the selected item(s). Click Yes.
Once you choose to delete a Custom Field, all references to it will also be deleted. It is recommended that you create a new Custom Field and unassociate the old Custom Field from the project(s) rather than deleting an existing one.