Abstract: An apparatus for forming a port in a liner installed in a conduit having a lateral opening inwardly overlaid by the liner so that the port coincides with the lateral opening, including a carriage adjustably positionable longitudinally within the liner adjacent to the lateral opening in the conduit; a brake for locking the carriage in fixed position in the conduit; a power driven port forming tool borne by the carriage in substantial radial relation to the liner for adjustable movement outwardly to liner engagement and inwardly to retraction therefrom, for adjustable movement longitudinally of the carriage, and for adjustable rotational movement about an axis longitudinally of the carriage; control means for controlling the position of the tool on the carriage from a position remote from the carriage; and a television system having a camera mounted on the carriage having a view of the tool and a viewing screen at said remote position.