Turn off the NVR or DVR, make sure its unplugged
First you will want to take the top of the NVR off. To do so remove the 3 screws on both sides and 2 on the back of the NVR
With the top off and the Hard Drive in the NVR, connect the Power and Sata (Red) Cables in the appropriate slot.
Once you have the Hard Drive connected correctly you need to line it up with the 4 holes on the bottom of the NVR and use the screws provided in the box to tighten the Hard Drive to the NVR.
After you have the Hard Drive installed put the cover back on the NVR and screw it back together. With the Hard Drive installed you are ready to initialize (format) it