well i found out if you NVA and you chose the kit with the shovel chose the shovel and press G over the tunnel and you can pick it up and where you want to place it chose the shovel again and press use button i forgot if its E or FIRE button or G again and you can put it near the enemy base so you all can attack it hehe and if you are the AMERICANS you can use nadeds or the bozuka to blow up the tunnel