Hello Jerry , you have to remove the ladder from the sleeper . First reason : the color isn’t the same. Then you have to do « your own snap assembly « with the ladder, you need to do a plastic strip and you will glue to the top of it. Later, when sleeper and fuel tanks will be assembled, you will slide the ladder strip into the groove between sleeper floor and sleeper body. You will correct angle too. Second reason : in case of shock, your ladder will drop but won’t be broken. I use this kind of assembly with many fragiles pieces of my models ( mirors for example) , it gaves me satisfaction, moreover you get a clean assembly.