I am assuming that you have the wireless-capable version of this HP printer ... correct? Is so, it should not have any difficulty connecting to a Wi-Fi network provided by your 802.11n AirPort Extreme Base Station (AEBSn). Note: I actually have the 6500 version of this printer and have not had any problems connecting it to my AEBSn nor printing to it from either OS X or Windows clients.
The basic steps are: 1) Using the printer's front panel, configure the printer to join the wireless network, and 2) Install the appropriate printer drivers (typically available with the installation CD that came with your printer or can be downloaded directly from HP Support).
Which part are you having trouble with?