Click the Local Repositories link under the Administration section
You will see all the local repositories that have been created.
In this screen you can add/edit/delete/purge a local repository.
You can purge a repository if it has a default Purge Configuration, otherwise the purge icon is disabled.
All fields are mandatory.
Adding a local repository will automatically create a default Purge Configuration for that repository.
The default local repository location comes from the settings of the user running Continuum. The location cannot be edited within Continuum, but can be changed by specifying it in ~/.m2/settings.xml.