OT: 87 Mustang 5.0 Serpentine tension pulley removal

[hpbear101]

My son has a 87 Mustang 5.0 and the serpentine tension pulley is shot. Got the new pulley, but can't figure out how to get the old one off the spring loaded arm. Ranther than a bolt and washer holding the pulley on, it looks like a stud with a groove that you would expect a split ring to be on, however the ring holding it on is not split. Any idea's?
Tom

[hpbear101]

Got it, was pressed on, my son had already removed the split ring.
Tom