How do you get out and adjust the hood bumper on the center support?

whats the secret to the hood bumper bolt on the center support by the hood latch? Trying to clean up and paint the support and the bolt won’t move. Has a funky clip on top I haven’t seen before. Thanks! Oh yeah, it’s a 70 GS Part

 

Closer picture of the bolt in question.

 

Use an open end wrench on the top part of the clip and loosen it a quarter turn so you can turn the rubber bumper stud up or down. Lock it back down when you get the right height.

 

You have to twist the lock collar to the left a 1/4 turn

 

Cool, that’s what I thought but wasn’t sure. And of course, lock collar is now loose but the bolt still won’t turn. WD 40 time.