How can I attach/detach the lid for my Truma portable fridge/freezer? 

This is a simple and swift process: Open the lid and push it past the stop until the lid can be detached. To attach the lid, push it vertically onto the stainless steel hinges until both sides engage.  

Please note that the mounting side for the lid can only be changed on the following models: C60, C69 DZ, C73, C96 DZ, C105