Enter the username: user and the password user (Note: If this doesn't get you in, hold the reset button 30 seconds and it will factory default the unit to user/user)
Once logged in, click on Wireless at the top, then Primary Network on the left. You'll see the screen similar to what you see here. Change the WPA Pre-Shared Key to your desired password..
Note: We recommend changing the Network Name when changing the password. Some devices will not prompt you for a new password if the password on your WiFi network changes. so you don't have to wade through all the steps to make your computers or devices "forget" the network so you can put a password in.
Click apply at the bottom of the screen, and log into your new network when it shows up. It can take up to 5 minutes for your devices to see the new network names.