Since they could not get him to Jesus because of the crowd, they made an opening in the roof above Jesus by digging through it and then lowered the mat the man was lying on.
NIV
And when they could not get him to a place in front of Jesus because of the throng, they dug through the roof above Him; and when they had scooped out an opening, they let down the [thickly padded] quilt or mat upon which the paralyzed man lay.
AMP
And when they could not come nigh unto him for the press, they uncovered the roof where he was: and when they had broken it up, they let down the bed wherein the sick of the palsy lay.
KJV