There are gaskets on the windows and doors in order to prevent the caravan from getting water from outside and to provide thermal insulation. Over time these seals wear out and need to be replaced.
When changing the gasket;
The first step is to remove the door trim. The challenge is not to break the ties. It can be dangerous given the fragility of the cardboard piece.
Then it's time to remove the deflector (small window that can rotate). Once you've figured out how to attach it, remove one of the screws and drill through to remove the rivet on the outer skin. Of course you should then remove the old gaskets and clean the inside so that the new ones hold well.
Installation of new joints; It is suitable for millimeters. Armed with a flat screwdriver to remove it and after some trial and error figuring out how to get your hand into the opening, the assembly of the lathe and windshield wipers is almost a formality. Gluing the door seals is also no problem, they fit well in the groove intended for this purpose.
Clean the inside of the door and vacuum the many pieces of glass there (someone in the past may have wanted to come in…).
apply rustproofing and install a new plastic sheet (initially a garbage bag) to close the door.