Using a prying tool like a Spudger, pry open the bottom half.

There are some locking tabs on both the bottom half and the main body. There is a specific tab near the COM port which makes it tougher to pry open. It may be easier to pry from the LAN port area instead. Continue from that spot along the side towards the front audio jack and keep going until the bottom half easily comes off.

Remember to take out the MicroSD before continuing further