Step 2: Remove The Screws
You're going to need to start by removing the screws. There should only be one, or 3 if you have the rack mount brackets on it.
If you have the rack mount brackets, you need only remove the top screw(s), you can leave the bottom ones on.
Then, look at the bottom of the router near the back (side with the ports) and find the lone screw and remove it.