Start: Attach an EZ-curl bar to the lower cable. Stand facing the weight stack, about a foot in front of it. Grab the bar with an overhand, shoulder-width grip. And hold it at arms length, in front of your thighs.
Finish: Pull the bar up until your upper arms are parallel t the floor. Pause, then slowly lower the bar back to the starting position.
For more shoulder comfort, stand 2 to 3 feet away from the stack. This shifts some of the work to your rear delts and traps. Your elbows come back as well as up, and your forearms are almost parallel to the floor at the top position.