A method of implanting a prosthesis in a patient at a treatment site includes advancing an outer catheter of a prosthesis delivery system in the patient and advancing an inner sheath and a guidewire lumen of the delivery system from the outer catheter to the treatment site along a guidewire while the outer catheter remains stationary relative to the patient. The method also includes locking an apex release lumen, a sheath lumen and a guidewire lumen within the apex release lumen, with respect to an outer catheter and rotationally locking the apex release lumen, the sheath lumen and the guidewire lumen. The apex release lumen, the sheath lumen and the guidewire lumen are threaded onto a guidewire and directed into a patient and the apex release lumen and the sheath lumen are unlocked with respect to the outer catheter.