How do I reset this phone?

Just power on holding up and it will ask if you want to erase all data. Press 1 to erase and y to confirm.

Power on holding the center button and it will ask you if you want to hard reset. That’s it.

Use the Clear Storage option in the Start > Accessories menu.

or

Press and hold both soft keys while powering on the device. the timing can be tricky but it will work if your persistent.

You can always use the Master Reset from system tools, or just make sure the Q9h is off, then hold down E and Z on the keyboard, then turn on while holding the E and Z. That’s it.