I have two subs and two amps The first sub and amp are hooked up already Can I and if so How do I hook the other amp up to the first one?

 

Depending on the amp, it should have some sort of pass through thing where you can plug the RCA cables from the first amp to the second without running more RCAs from the headunit. Then you just need your power, ground, and remote turn on and you're set.