Wash and dry milk carton completely or purchase unused cartons. Put the cans into the cartons first, then add the drink and soup packets diagonally. Stuff the granola bars, gum, jerky, trail mix, and fruit rolls in around the cans. (This packing requires some time, but it does work.) The candy can be strewn throughout the carton, filling any small gaps. Tuck the gum into gaps or wedges wherever it will fit. (The crackers will undoubtedly be crushed, but since they will be eaten in the soup, it doesn't matter.)
When the carton is packed full (and it will be a very tight fit), staple the top of the carton shut. It's easier if you have someone hold the top shut while you staple it. Next, tape the top with duct tape, and then strap the filled pop bottle to the carton with the duct tape. Tape a contents list and a menu to each carton and record the assembly date.
Your kit is now completed. List the assembly date and rotate the kits every two years so that the food retains its nutritional value and remains fresh.