Hi minihack said almost everything:
-it must be screw in the metal upper plate , if not: "reset loop"
-+ or - doesn't matter, just solder pin cable 4 and 5 with a standard pc front panel switch cable and then connect it to the power switch pins on the motherboard
-to be functionnal, the touch switch need to receive 5v so use the purple cable on your atx power supply (for me, i make an intermediaire connection to be able to disconect the touch switch board from the psu!)
and final, we don't care about the power led, we don't need that the touch switch board control it so simply solder a standard pc front panel power led cable and then connect it directly on the power led pins on the mother board, it is easier and you will have the led blinking when in sleep mode . So what else? (it is not related to the nespresso thing with george clooney!
)
VOILA
nothing very complicated, hope that it could help for some people