Also, when you first turn it on you will have to bypass the activation screen. Just tap the 4 corners of the screen in the following order:
Another tip is to turn off the cellular radio to get better battery life (since you won't be using it).
You have to go into the testing menu to turn off the radio.
Open the dialer, type *#*#4636#*#* as if you were dialing the number. Don't press send.
The Testing menu will open.
Select Phone Information.
Scroll to the bottom of the screen.
Press the toggle button "Turn off radio".
Press Home.
Unfortunately, every time you reboot the DX you will have to turn the radio off again. You will not have to bypass activation after a reboot though, only after a factory reset.