Find the EMP device in level 4 and activate it when RubiA is nearby (you might have to lure her). After she's stunned, just walk up to her and left-click.
on i see，I have to get to the level four.but i cant even get through the level two…
I found lvl 2 to be the most difficult in avoiding her. Don't rush and listen carefully. Or you can open all levels at the bottom of the options menu.
