This is easily findable on the Google, but I thought I should include it here in case the prior post drew you in via a search engine. If you want to accomplish the same thing in IIS6, do the following (your AdminScripts folder mileage may vary, I'll use the default on a Windows 2003 server here):
High level example:
C:\Inetpub\AdminScripts>cscript.exe adsutil.vbs set /w3svc/<siteID)/SecureBindings "IP.Of.The.Site:443:Web.Site.Com"
Low Level Example:
C:\Inetpub\AdminScripts>cscript.exe adsutil.vbs set /w3svc/123456789/SecureBindings "127.1.2.3:443:WebServices.SecureCompany.com"