Destroy the first molecular cannon | Reclaimer Halo 4 Guide

After cleaning the area up, go down. Get to the marked target, eliminating all enemies on your way. When you pick up an indicator, aim a ship nearby rocks. When the indicator is ready again, aim at molecular cannon. After destroying the target, return to the highest level of Mammoth.

Switch on the left turret again and fire at Banshees and shooters on Phantoms. When you get to the next target, destroy all vehicles you can aim from the turret. Then, using a sniper rifle, kill as many opponents as you can.