Picked up new upper inner pins for my 54, went to put them in Friday night and couldn't see figure how they come out, I removed both threaded end cap bolts, and it seems that the pin its self is threaded into the mount best way to remove / Install?
If you have the two end caps off already (I'm assuming you must have the spring tension released) you should be able to loosen the clamp bolt in the center and thread the inner pin out of the upright. You may have to spread the upright VERY slightly to get it to break loose if it hasn't been adjusted for 30 or 40 years. You should be able insert a allen wrench in the end that had the grease fitting originally to get some leverage to turn the pin out.
Have a look see at this. http://www.chevytalk.org/fusionbb/showtopic.php?tid/218134/ Some guys on here turned me on to this. A Chevy manual helps out also! Good luck!!!