How to remove this kickstand without destroying anything? I have a 70's Schwinn Collegiate. It has kickstand that's welded to the frame. How can I remove this kickstand from the housing? Looking at the bottom, I can't tell if this pin needs to be pushed in or pulled out.

I want to be able to put it back together afterwards.
The pin needs to be pulled out.  You can remove it using a wrench inserted in the kickstand for leverage to push the ring and that will loosen up the pin. If you need a visual, see this video.  Hope it helps.