|The manual will detail how to do a reset to factory defaults. If you lost your manual, try looking it up online on D-Link's website.|
Typically, with the unit powered on, you press and hold the reset button for 10 seconds.
Once you've successfully reset the unit, you're going to need to know the default IP address of it's management interface and the default login information as well. Both can also be found in the manual.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.