I would like to thank the person who installed the duct work in my home especially on the 2nd floor since they did not install any returns on the 2nd floor. The only return I have is on the 1st floor underneath the stairs. This creates a big temperature difference especially during the summer months. Is there anything that can be done to remove hot air during the summer without tearing up so many walls? Can something be installed in my attic as a separate unit to suck the cold or hot air out? Or can someone recommend anything else? Thank you!

Yes. See the ductless-split recommendation at the bottom of this page:

http://www.heatpro.us/service/splitlevel.htm

www.heatpro.us energy businessmen's knowledge

Yes, you really have to find out the MAKE and MODEL to get good answers. There IS more than one machine made.