This trick requires either the Law or the RPG, and the M16, ration and supply marker. Wait until Pupa stops and fire a rocket at the large cylinder console on its front. To avoid the electric shots. Do not stop moving. When it launches its lighting rods, take out a few near you with the M16 and lay flat on the ground until the lighting stops and keep firing. If you are running low on rations and ammunition, use the supply marker to call in more. Once it is destroyed, fire a rocket at the hatch on top of its head. You need to take the "programs". It does not matter which ones you take out.