use solder/heatshrink, or use butt connectors. the remote is a hot 12v source so you dont wanna have it arc out on you.
as for connections . it should go from remote on radio( usu. blue, most decks have 2, one for pwr antenna, one for amp, if you install and amp turns on then off, most likely wrong one, just switch them)
anyway, from radio to remote line on both amps. what setup are you going with? using factory amp?