A surgical tool apparatus comprising: an end-effector apparatus comprising: an end effector having a base, wherein the base comprises a cylindrical coupler (562, 564); a conduit having a distal end coupled to the cylindrical coupler (562, 564) and a flexible portion at the distal end; and a control link extending axially through the conduit and the base and having a distal end coupled to the end effector, the control link having a flexible portion at the distal end, wherein the control link is moveable along the conduit and is coupled to a pivotable jaw (554, 556) of the end effector to cause movement of the jaw as the control link moves inside the conduit, and wherein the conduit is operable to rotate to cause a rotation of the end effector; and a tool positioner apparatus comprising: a tool positioner having a central opening (152, 266), wherein the central opening (152, 266) is operable to receive the conduit of the end effector apparatus; and a tool holder disposed at a distal end of the tool positioner, wherein the tool holder is operable to secure the cylindrical coupler (562, 564) of the end effector apparatus by means of a threaded fastener; wherein the tool positioner is operable to move to position the tool holder disposed at the distal end of the tool positioner during a surgical operation; and wherein the cylindrical coupler (562, 564) of the end effector apparatus is secured within the tool holder by means of the threaded fastener and the conduit is received within the central opening (152, 266). an end-effector apparatus comprising: an end effector having a base, wherein the base comprises a cylindrical coupler (562, 564); a conduit having a distal end coupled to the cylindrical coupler (562, 564) and a flexible portion at the distal end; and a control link extending axially through the conduit and the base and having a distal end coupled to the end effector, the control link having a flexible portion at the distal end, wherein the control link is moveable along the conduit and is coupled to a pivotable jaw (554, 556) of the end effector to cause movement of the jaw as the control link moves inside the conduit, and wherein the conduit is operable to rotate to cause a rotation of the end effector; and an end effector having a base, wherein the base comprises a cylindrical coupler (562, 564); a conduit having a distal end coupled to the cylindrical coupler (562, 564) and a flexible portion at the distal end; and a control link extending axially through the conduit and the base and having a distal end coupled to the end effector, the control link having a flexible portion at the distal end, wherein the control link is moveable along the conduit and is coupled to a pivotable jaw (554, 556) of the end effector to cause movement of the jaw as the control link moves inside the conduit, and wherein the conduit is operable to rotate to cause a rotation of the end effector; and a tool positioner apparatus comprising: a tool positioner having a central opening (152, 266), wherein the central opening (152, 266) is operable to receive the conduit of the end effector apparatus; and a tool holder disposed at a distal end of the tool positioner, wherein the tool holder is operable to secure the cylindrical coupler (562, 564) of the end effector apparatus by means of a threaded fastener; wherein the tool positioner is operable to move to position the tool holder disposed at the distal end of the tool positioner during a surgical operation; and wherein the cylindrical coupler (562, 564) of the end effector apparatus is secured within the tool holder by means of the threaded fastener and the conduit is received within the central opening (152, 266). a tool positioner having a central opening (152, 266), wherein the central opening (152, 266) is operable to receive the conduit of the end effector apparatus; and a tool holder disposed at a distal end of the tool positioner, wherein the tool holder is operable to secure the cylindrical coupler (562, 564) of the end effector apparatus by means of a threaded fastener; wherein the tool positioner is operable to move to position the tool holder disposed at the distal end of the tool positioner during a surgical operation; and wherein the cylindrical coupler (562, 564) of the end effector apparatus is secured within the tool holder by means of the threaded fastener and the conduit is received within the central opening (152, 266).