When can I spend viktor's hosted power counter to do 1 brain damage?

Also it costs 1 click to break each sub routine right?

Power counters may be spent during any of the paid ability windows. 2.0 bioroids do not work on the same 'click once to break one subroutine' basis as 1.0 bioroids. You may spend two clicks to break up to two subroutines. There is no option to spend less than two clicks on the card. It's like battering ram, you can't spend less than two credits if you only want to break one routine.