To remove the circuit boards you can remove the 4 short screws as shown.

For the top board you can pry around the edges (use plastic or wood tool). Note that there is a connector on the back that connects to a board inside the compartment on the other side.

The bottom board I recall was just loose. Beware of ruining the other ribbon connector (yellow) attached to it.

For the top board there is a speaker wire (yellow) going behind it that will keep this from being removed. It is thin so it could be broken easily.