ok..
a switch opens and closes the circuit it would be like you cutting the wire in half and then touching the bare ends to turn it back on..
run the remote wire from the head unit to where you will mount the switch then cut the wire...
attach one side from the head unit to one of the tabs on the switch.. then use the other end..(going to the amp to the other tab on the switch... unless you have a light up switch where there is three tabs..
then you use the two that dont say negative. the negative you will ground so when you turn the switch on.. it will light up.