Upgrading DS 7.6 HF1 to HF6 - IIS

I'm currently running DS 7.6 HF1, and I'd like to upgrade to HF6. I take the following steps in Symantec Installation Manager:

- Install hot fixes.

- Select all (Deployment Solution, ITMS Management Views, and Symantec Management Platform 7.6 HF6).

- Accept license.

- Install Readiness Check shows all recommendations OK.

I am stopped at the following error message:

"SSL Setting is set to true for web site 'Default Web Site' and 'SecureBindings' is not available with this website, bind Secure port with the selected website before Installation.

Sadly, I'm not all too familiar with IIS (my workplace is all httpd). How can I fix IIS to let the HF6 update work?

Thanks!