Please click Sign Out in the top right corner of any page and you will be automatically logged off as you will see the "You Have Successfully Logged Out" page.  At this point, you can click on Sign In and then log in as another user.

 

Just remember, once you click on "Sign Out", you will then have to log in with your user id and password and click on "Keep me signed in" to have the automatic login feature reset to your user id and password.