The Skulls in Mission 29 are very difficult to defeat in Metal Gear Solid V: The Phantom Pain. Really? Many have tried of beating the Skulls, but they find it extremely difficult. So to clear the difficulty check this guide below which will help you defeat them with ease and also how to get an S-Rank in this Mission in MGS V: The Phantom Pain.
How To Beat Skulls
Before you start the mission make sure you have your preparations done. You need an Assault suit, a machine gun, drum grenade launcher, micro-ultrasound, C4, partner - demure with a fatal rifle. Now After the cutscene is over mark the four skulls with your binoculars and head right to the hangar with the aircraft. Place 6 to 8 C4s on the door and run away, as the skulls approach the door Blow up the door. There should be at least 75% of the damage done by 2 bolts. Just keep repeating this process and after your out of C4s run away and shoot the skulls with the grenade launcher also ask Quiet to change her position.
Now Quiet will keep shooting the skulls and till then you shoot them and avoid their fire and stunts. Quiet will try her best to remove their armor and till then you keep shooting them. Keep moving all the time to restore health in the building in front of the hangar.
Note: After winning - be sure to evacuate Skulls to unlock the costume "Parasite".
How to get S-Rank
ALM 48 machine gun with some explosives (C4, Grenade Launcher, Grenades) and Buddy Quiet is perfect to get this mission done. All you need to do is to hide in the hangar from the start but, don't forget to mark the Skulls when the fight starts to know their current location and health status. Plant a C4 in front of the hangar and lure them into it. Now you can shoot the enemies through the hangar windows with your MG.
Hint: Make sure you run away as the spikes come out of the ground, they will explode and instant-kill you.