In vs2010 you should be able to do a build or rebuild by right clicking on your solution which will create new dlls with your source changes. You can then copy the new dlls to the \bin folder on your server or add the dlls to the SmithCart install pa zip if you need your changes as an installable package.
Here are some links that explain how to build and create a dnn module:
http://www.dotnetnuke.com/Resources/Wiki/Page/Manifests.aspx
http://stackoverflow.com/questions/1198217/dotnetnuke-module-installer
http://www.adefwebserver.com/dotnetnukehelp/DNN_PackageModule/ProtectingYourModule.htm
http://www.dotnetnuke.com/Resources/Wiki/Page/Automated-DotNetNuke-Module-Packaging-MSBuild.aspx
If you have customized your Smith Cart software and you need further assistance, you can take advantage of our
Developer Consultation Time access, and our technicians will make every effort at their disposal to help you resolve the challenges presented within your customized software.
Thanks,