amp wiring harness for JBL original unit

Found an MTX thunder 2000 10 " while helping a friend move,
I don't want this to be big project, with like replacing the head unit and everything, I just want to be able to use that subwoofer.

I have the nine speaker JBL as far as I understand, it's not touch screen but It says JBL it has wireless headset and a CD changer,

I know there is a way even if I have to simply use a splitter on my aux cable,

Please help me, this will complete my dream!!!