Complex sentence: The M-ATV's roof mounted turret is capable of mounting either an M240 machine gun, a Mk 19 grenade launcher or, a BGM-71 TOW Anti-tank guided missile, all of which can be operated either from the turret or remotely inside the cabin.
Split into simpler sentences: The M-ATV's roof mounted turret is capable of mounting weapons such as a M240 machine gun, a Mk 19 grenade launcher or, a BGM-71 TOW anti-tank guided missile launcher. The roof weapons can be operated either from the turret or remotely inside the cabin.