Use the Hide option to remove a contact from your Tango Friends list:
- Launch Tango and navigate to your Friends list
- Find the contact you want to remove and tap on their picture to view their profile page
- Tap on the 3 Dot icon located in the top right hand corner
- Tap on Hide this person
To add the contact back to your Tango Friends list, navigate to the Settings >> Privacy >> Hide List and select the contact you want to Unhide.