Merge meetings and webinars

[amlamb]

I run public webinars that require registration. I have accidently created both a meeting link and a webinar link which both have several registrants already. Is it possible to merge a meeting into a webinar so that registrants don't need to sign up again? Or do I need to send an email to all the meeting registrants and ask them to sign up for the correct link, under the webinar. Help!