From NZXT website:
"Begin with the front panel by grabbing at the bottom of the case, and pulling up at a 45 degree angle to remove the panel. It is secured by eight plastic push pins, so be sure not to pull at too extreme of an angle or you will risk breaking them off.
With the front panel off, you may not remove the top panel by grabbing at the front of the top panel and pull front to back at the same angle as the front panel.
These may require some force to remove due to the fitment at the factory, but you should always try not to force anything to the point that it will bend or break."