The game can always be reset to the beginning of a campaign. To do this, you simply need to repack certain game elements to their orignal boxes. See the following rules for the list of contents in each box:
• Box 1 Components (spoilers)
• Box 2 Components (spoilers)
• Box 3 Components (spoilers)
• Box 4 Components (spoilers)
• Box 5 Components (spoilers)
The rest of the game materials are the basic elements the campaign starts with. To see a list of these see the rule Components.