95 Suburban Hinge Pin

I have a 95 Suburban 191K miles and I need to replace the driver side hinge pins. They are worn really bad and are causing the door to sag and difficult to close. I have the spring out and now need to remove the pin itself. The problem is, since the pins are inserted from the bottom up, I can't figure out how to remove the retainer cap on the pin that seems to holds it in place. If it is not the cap, then how is the pin held in place? If I pound it out and destroy the cap, how do I hold the new pin in place? Thanks in advance for all your help.

My new pins came with caps. I just popped the old caps off with an old screwdriver.