Eagle said
I have a “how to do” about this somewhere. It involves spreading the closed ring apart by twisting one end of the ring just a bit so the two ends are no longer aligned and the stud will slip on, and putting it in a padded vice (in the middle at the bottom, leaving the open part of the ring at the top) and use a hammer and small block of wood to align the two again, You can pound the rings closed more if needed or align them together. I’ve done it and not that hard. Peter   

You are exactly correct. I’ve done this before. If you spread the ring open, it’s almost impossible to get it closed up tight. Twist it open enough to get it through the stud, and then twist or hammer it back in alignment.