In this section of the SnowRunner guide you will learn how to sell trailers in the game.
In Snowrunner, trailers save time when transporting more goods. Those left on the map are also a good way to make extra money. In order to sell the trailer you must drive with it to the nearest TRAILER STORE. You'll find them either in different locations on the map or in your garage.
Drive the car into the store and when you enter the shop option, select the trailer you currently have attached (it has an icon in the corner) and click sell.