You access your previously created archives in the in the Project Management section under the Archives area. In the Archives are under the Column "Archive Name" you will see a list of all the archives you have created for your project, to view any of the created archives click on the black view button or the archive name. Once you click on the archive you are taken directly into the Project Management section of the archive.
All sections of the normal project are available in the archive view, however read only and export functionality is available. Meaning you can see all the content and export any of the content (same as a normal project) but you cannot change any of the content, in order to preserve the integrity of the data.