Running existing site through SSL

I have a self hosted license. I have the chat embeded in a popup pn my site. My main site has an SSL certificate, kayako is on a different server and not running SSL. Can I simply install a certificate and run kayako with SSL?

The issue is my main site is shoing up as mixed content due to kayako not running SSL.

Please keep in mind I am not a web person, so I probably didn't explain this very well.

Thanks