a flat bench. for a beginning, place one dumbbell on each of the sides of the bench. now place your right knee at the end of the flat bench, and on the other end of the bench, place your right hand. make sure your upper legs and your upper body are making 90 degrees angle. also your upper body should be parallel to the bench. with your left hand pick up the dumbbell from the left side of the bench and make sure to keep your back straight, just like on picture 1. that will be your starting position.
slowly start pulling up the dumbbell. pull it up all the way 