To loosen the plastic standoffs, use a pair of needle nose pliers (or similar) and squeeze the tops to free the board. Once it is free, flip it over onto the video board.
The cable from the power supply to the video board does not come off easy. To ensure that the connector will not break, it may be necessary to remove it from the video board. For that, remove the video board.
Remove the three Phillips screws. They are M3x5