We will be installing the NH-D15S in our X79 system, which makes installation quite easy as there is no need for a backplate. To start off installation take the four bolts and attach them to the LGA2011 socket as shown in the below photo.
From here you can install the mounting bars. The orientation we have them in will have the heatsink towers of the cooler sitting in a vertical orientation. You can have flip them to have the heatsink towers in a horizontal orientation.
Now apply the included thermal paste on your CPU and remove the fan from the center of the cooler. Very carefully place the cooler on top of your CPU lining up the screws on the cooler with the pegs in the mounting bars. With the included screwdriver fasten the screws. Once again another very easy installation from Noctua. Be sure that you have cooler in the right vertical orientation. To check this make sure you can read the Noctua logos normally on each heatsink tower. If you have the cooler in the wrong orientation it will block your first PCI-Express slot.
Now all you have to do is reinstall the fan and connect it and you are good to go. I decided to remove my graphics card when doing this installation. While it could have been done with the graphics card in, removing it made it easier to reinstall the fan. As you can see there were no issues with PCI-Express clearance.
Looking around the cooler we can also see that memory on either side of the cooler is not blocked at all.