1. Open your app
2. Select "Contacts" from the bottom menu bar: 
3. Tap contact you wish to manage: 
4. Scroll down and select "tags": 
5. You can edit this contact to a current tag or create a new tag by selecting the "Green Plus": 
6. To delete Slide the Tag to the left and select the "trashcan": 
7. To edit select the Tag then select the "Gear" : 