You will need to have the Access Point name and the Network key both in hand, in order to connect the printer to the wireless router.
Press the Setup button:
and use the < or the > button to select the Wireless LAN Setup. Then press OK.
Use the up or down button ^ or v to select Yes, then press OK.
When wireless is enabled, the wireless light will be blue:
Select 'Easy Setup', then press OK.
Select the access point name of your own router, then press OK.
When one of the shown screens is displayed, enter the Network Key for your router, and then press the OK button. Note that you must enter capitalized letters properly for it to work; character entry modes are switched between by pressing the * key.
Verify that the network key is properly entered, then press OK.
If 'Connected to the Access point' is displayed, press OK, and you will be returned to the Setup screen. That kind of completes the process.
If 'Failed to connect to the access point' appears, press the OK button, make sure the network key you have is correct, then enter it again, carefully.
When the process is over, press the Copy button to return to Copy/standby mode.