Item description:

Load the save & head through the door you will be prompted to go through or not just go through & you will have to defeat the 3 bosses for the trophy to pop

Boss Fight (Stage 1) - Aim for his head and avoid his rolling attacks, magnum again the gun of choice.

Boss Fight (Stage 2) - Run! This goes on for a while, I found moving the left analogue stick in a complete circle was the best way.

Boss Fight (Stage 3) - Avoid his shockwave attacks and shoot the doll in his hand, when he hides the doll and slams his fist on the floor run to it to climb up. When on his shoulder get the Submachine gun out and shoot at the doll inside his chest pocket.