To delete a custom channel metadata field, proceed as follows:
Highlight the entry you want to delete in the list of channel metadata fields.
Then, click the [ ] button at the top of the list. A confirmation dialog will open.
Confirm with the [Delete] button. A second dialog box will open, in which you will be informed in how many places the metadata field is currently in use.
If you still want to delete it, click [Delete]. The custom channel metadata field is deleted.