How Do I Uncouple Class 380?

I wanted to do a timetable on Cathcart circle and it showed me that I need to uncouple train but I didn't know how

 

Press the 1 button on the cab screen, then 4, then 1 again. That should do it

 

Play the first Scenario, it guides you through coupling and uncoupling.

 

Thank you very much

 

Thanks I'll play the first scenario