You would insert a catheter into the femoral vein going towards the heart. During this process the femoral vein would get enter the inferior vena cava and then enter the heart at the right atrium. Inside the right atrium you would have to get into the right ventricle and the into the pulmonary trunk which divides into left and right pulmonary arteries. You would want to continue into the right pulmonary artery and select subsequent divisions which would perfuse the lower segment of the right lung.
