1) FIRST! Turn the CURRENT KNOB to zero ( yellow circle ).
2) SECOND! Turn the VOLTAGE KNOB to zero ( yellow circle ).
3) Press the GENERATOR OFF button (red circle).
4) Wait a minute and then turn off the main valve (blue rectangle). Ignore the red and yellow outlines, they’re for something else.
5) Remove your sample.
6) Replace the shield.
And clean up your damned mess! Thank you very much.