Hi 2001 grand prix gt after maket

Sony cdx-gt50w
kicker L5
kenwood 9103d mono amp

I just purchased new kenwood 6x9 for the rear deck how can i hook these up to the amp so that the subwoofer and the back are being powered by the amp I changed out the amp with a older two channel and dont think i'm doing it right they sounded like crap. I just need some good advice from smart people thanks for the help