There is a piece of clothing stuck inside the tub, caught between the two drums.

You have to find one of two ways to remove the upper part of the machine.First, unplug the machine from the power source on the wall.By the upper part , I mean the lid of the drum. The first way is to check the back of the machine for a plate cover that is taller than the lid and cover of machine. If that plate is present then that plate has to be removed. If not , then go to the front of the machine and with a large flat head screw driver insert from the front on each corner and pry the lid up . you will see various styles of clips that hold the drum lid down and you will use the screw drivvito relase the lid . From there you should be able to remove the debris. To re-assemble simply drop the lid and re-secure the drum lid by pushing down on the front.