This trophy guide is for Well That Was Easy
which requires you to shoot Face McShooty in the face.
This is an incredibly easy trophy to earn and only requires you to unlock the Thousand Cuts area which is a part of the main storyline.
As soon as you arrive in the Thousand Cuts area you will see a yellow exclamation mark indicating a new interactable quest. Face McShooty will be screaming and hopping around. Accept the quest, and then oblige him by unloading some bullets into his skull.BAM!
Your trophy is earned.