How to delete a CCK field
CCK fields in Drupal 7 can be removed directly from user interface. Simply login as an administrator user, open “Structure” section and click on “Content Types“, see the image below:
In the new page you will be able to see all the content types you have in your system. Simply press the “Edit” button next to the content type from which you want to remove the CCK fields. In the new window click on “Manage Fields” button which will show you the list of all CCK fields, see the image below:
In order to delete a CCK field simply press a “delete” button next to it.