In order to do this, please follow the next steps:
1. Open the post/page in the edit mode;
2. Make sure that "PDF & Print" checkbox is marked in the Screen Options bar;
3. There is the PDF & Print settings field at the bottom of the editing page.
4. Find and check "Do not show PDF & Print Custom fields on this page" checkbox.
6. Click "Save Changes" button and check the result.