You can change a field to regular text, so that it is no longer updated. After you change a field to text, you cannot change the text back into a field.
Select the field and choose \<emph\>Edit - Cut\</emph\>.
Choose \<emph\>Edit - Paste Special\</emph\>.
Click "Unformatted text" in the\<emph\> Selection\</emph\> list, and then click\<emph\> OK\</emph\>.