Houses where Jesus lived had flat roofs made of clay and covered with tiles. The process of making a hole in the roof can be explained more clearly or made more general so that it may be understood in your language. Alternate translation: "they removed the tiles from the part of the roof above where Jesus was. And when they had dug through the clay roof, they lowered" or "they made a hole in the roof above where Jesus was, and then they lowered"