A method for installing a stent graft in therapeutic relation to an abdominal artery aneurysm includes the steps of advancing the stent graft over a guide wire and an introducer sheath, followed by advancing a main catheter over the guide wire and the introducer sheath. An inner catheter in the lumen of the main catheter is pulled to cause a magnet-carrying extended arm to encounter a kick plate in the main catheter lumen and to exit that lumen through an exit opening formed in the main catheter. A mating catheter having a magnetic tip is advanced over a contralateral guide wire and manipulated until the respective magnets engage. After specific positioning of the contralateral guide wire, the magnets are decoupled, the mating catheter is retracted, the inner catheter is pushed to return the extended arm into the main catheter lumen through the exit opening and the main catheter is withdrawn.