Screw the Power Supply Unit to the back of the case
Open the accessories box that came with your Define R5 Case.
Take out the 4 black Power Supply Screws
Use these black screws instead of the chrome ones that came with the Power Supply Unit.
The black screws will match the case color.
Use your #2 Philips Screwdriver to attach the Power Supply Unit to the back of the case.
The PSU is held in place by these 4 screws.