Deleting a custom field from a workflow table is a two-step process:
Remove the source field from all forms using the Fields on Form tab. It will no longer display on the form.
Delete the source field from the workflow table using the User Defined Data form. This step is described in the procedure below.
To delete a source field from the workflow table:
On the Navigation menu, click Administration ยป User-Defined Data.
In the User-Defined Data form Area field, select All Workflows.
In the Source Fields tab grid, select the field that you want to delete.
On the grid toolbar, click Delete.
On the form toolbar, click Save.