How to enable SSL for an existing SharePoint site

First, configure the corresponding Virtual Site in IIS manager, assign a server certificate to it in "Directory Security-secure communication", and then enable SSL Security Channel in secure communication:

Then, specify the port used by SSL for the Virtual Site in IIS Manager:

 

Open "SharePoint 3.0 Management Center" and click "Alternate access ing" on the "operations" tab ":

Click the corresponding web application in the standby access ing.ProgramURL, change the URL from http: prefix to https: Prefix:

 

Done! Now you can try to use "https: //" to access your SharePoint site.