An apparatus 3500 is positioned within a preexisting section of wellbore 3575 having casing 3590. A new section of wellbore is drilled by a bit 3535 which is driven by a mud motor 3530 actuated by fluid pumped via passages 3540,3545, pressure chamber 3550 and passage 3555. At some point during the operation of the mud motor, the pressure drop across the motor will create sufficient back pressure to cause the operating pressure within the chamber 3550 to elevate to the pressure necessary to extrude tubular member 3525 off of mandrel 3510. As the tubular member is extruded off of the mandrel , the weight of the extruded portion is transferred to and supported by the drill bit. At some point a sufficient portion of the weight of the tubular member is transferred to the drill bit to stop the extrusion process due to the opposing force. Continued drilling eventually transfers a sufficient portion of the weight of the extruded portion back to the mandrel 3510. At this point, the extrusion of the tubular member off of the mandrel continues. In this manner, support member 3505 never has to be moved. Once the lining of the new section of wellbore by the expanded tubular member 3525 is completed, the support member 3505 and mandrel 3510 are removed from the wellbore.