After your first encounter with Birkin he’ll come back during the Sewer section, much more powerful. Here’s how to defeat him. Before entering powering up the trash compactor door make sure you have flash grenades and ammo. The fight will begin when you try to enter the trash compactor, with Birkin plunging his claw into the ground and destroying the door. The first phase is you dodging his claw while fire slowly covers the room. Simply run in a constant pattern to avoid damage. Once fire covers half the room Birkin will start clawing his way inside from the metal door, prepare yourself on the left side and once he’s inside run out. This is where things before hard, Birkin is unkillable and you must use the crane to damage him. Press the button on the right-hand side immediately and prepare Birkin for a hit. Wait till the holding crate is ready, a prompt will appear on the button, then unload on William’s giant eye. Once stunned, prepare the crate. Do this twice to take down Birkin.