The requirements are necessary to install a resolution of the display HDPI (800 × 800 × 480 or 400) or XHDPI (1280 × 720 or 1280 × 800) and, unfortunately, have root permissions. Once you download the apk from xda you need to move ( do not install it, move it! ) in the folder system / app and then repair permissions (rw-r-r-). Once done, reboot the device and everything should work, but if you do not find the app installed you may need a wipe of the cache.
The owners of Galaxy Nexus will use a much simpler procedure, only having to flash this file, and you try this launcher? Or would you prefer to keep Nova, Apex or one pre-installed?
