Take the drawer out and look up under the counter top. There should be screws holding the unit in place. Remove them and try again.
If this does not free the unit it may be that the flooring does not run all the way to the wall under the unit. In this case the compactor's feet are hitting the flooring edge, preventing its removal.
Try to adjust the foot pads by turning them clockwise to move the foot closer to the compactor's housing on both sides (note that some may be counterclockwise). This shouild free up enough space to allow the compactor to be removed.