Is there a way to change posts from private to public, vice versa?

Hi, is there any way to make a post public if the lock happens to be closed on that post (next to the trash can)?

I probably uploaded & posted the photos while I was in private mode, but I really didn't mean to be in that mode so when I switched back to public, I expected the status for my posts to change, but they seem to be "locked" in that state.

The trash can/delete next to the lock is clickable, but the lock is not. Do I have to delete and upload the photos again in public mode for them to be public? That would suck...

Thanks!