V4.5 or Later
- Navigate to "Messages".
- Swipe left on the chat you want to change or tap '+' and skip to point 4.
- Tap "Configure Chat".
- Tap the circle avatar at the top.
- Select the users you want to be in the single chat.
- Press 'Save'
Else if you just want a 1:1 chat just select one user then press 'Save'.
Customer support service by UserEcho