Validate the My Site Host and individual My Sites are on a dedicated Web application and separate URL domain error message

I am getting the following error in the the Central Administration's Health Report:

"Validate the My Site Host and individual My Sites are on a dedicated Web application and separate URL domain."

I tried to follow the instructions from the following site to create a new Web Application.

http://myspexp.com/2010/06/14/setting-up-mysite-as-a-different-application-2/

I get the following error:

"The IIS Web Site you have selected is in use by SharePoint.  You must select another port or hostname."

I have changed the name, but am unsure of changing the port. If I changer the port will the users need to manually enter it to get access to My Site?