How to Couple and uncouple a trailer safely.

The Correct, safe way to disconnect and to connect to an HGV trailer.
Connect to a trailer.
Disconnect from a trailer.
Couple to a trailer.
Uncouple from a trailer.
Hitching onto a trailer.
Unhitching from a trailer.
Drop and catch a trailer.
Couple up to a trailer.
What is the best way to couple up to a trailer.
Unit and trailer.  
Uncouple a trailer.