84 C20 Upper Control Arm question

[Handsome65]

Hey guys,

I'm rebuilding the front suspension on my 84 C20, and I am slightly stumped by the upper control arm. On each end of the pivot bar that connects the upper control arm to the frame, there is a cap / nut with a grease zerk on the end, and I cannot figure out how to remove it. It is very large, looks like it would require a 1 1/2" socket to remove. What's the trick to getting this thing off?

Thanks in advance for your thoughts!