If you only have a few enumerators and forms, you could work entirely locally and offline with a combination of instructions for Pushing/pulling forms to/from android devices directly from a pc and ODK Briefcase.
Is there a particular reason you need to work locally? The suggested way to install Aggregate is on Google's AppEngine. Installing Aggregate locally is going to require you to install Tomcat and a database which are challenging. Another option is to use the virtual machine (has not been updated to the latest version of Aggregate yet but should be sufficient).