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is pushed to return the extended arm into the main catheter lumen through the exit opening and the main catheter is withdrawn .