How do I reset the visitor history so that slide in shows up again for the user on the site?

Hi, I am trying to figure out how to reset the slide-in for users who have previously turned off the slide in. I had set it to be dormant after 7 days but have updated the slide and want to be sure all visitors see the new message.

I can't seem to find a way to reset the slide-in for any given slide.

Thanks for your help.