If you play Nod, you MUST!!! mine these tunnels, or, i prefere, mine the outside so they can't disarm them without getting hit by obelisk After that, If you choose tactic 1 you buy an buggy/APC/light tank/stealh/Flame, all of these work, then you rush AGT and park so close it can't fire @ you, destroy it with the weapon OR if it's destroyed, run into the AGT and playce C4 (all 4) or ION beacon! Tactic 2, buy a stealth suit and Nuclear beacon, then you follow the harvester into the base, You might want to train on this tho, as it took me 50-60 times to get in The trick is to stay behind the harvester untill it docks with refinery. then you run the BACK way into the Weapon factory / Refinery / Powerplant Its soo simple!