... and press the power on button a few times before removing the RAM.
Don't leave the power connector in the mains when opening the computer!!!
The PC case if isolated can float to an arbitrary potential so you will be at the same potential as the case. If you were to inadvertently touch something else that had a different potential (such as real ground), you could damage components due to the potential difference.The ground adapter I mentioned does just that, provides a ground to the pc case ( as long as the power supply is still in the pc), but has no power connection to the mains.