I activated before installing a certificate

I activated the plug in and i did not know i needed a ssl certificate. Now i do not know how to access the site to disable the plug in. I do not know how to access through FTp or any other way. We are a youth rugby league and i really need the site up for registration. I cant find a support email or phone number to get help.

The page I need help with: [log in to see the link]