You can add tags from the "Edit Tags" tab on content screens. However, if the creator has locked tag editing, you cannot add tags to the content. For any one piece of content, people can add a maximum of 10 tags, including any previously added tags.
1.Display the content for which you would like to delete tags.
2.Select the "+" button in the location where the tag is displayed. 
3.Select the "X" button next to the tag that you would like to delete.
You cannot delete tags that the poster added to their content, but you can delete the tags that other persons have added. When you delete a tag, your user ID is displayed in the editing history.