I have very basic/low level knowledge so i cant get too detailed but should be simple. Please help

My truck has an amp wired that ran sub before. It is still wired however now i want to run 2 6x9s. What do i need to adjust so the amp doesnt think its powering a sub but instead more treble and sound in 6x9s? Do i still run it out of the same rear wire feeds in the back of my cd player? Is it just a matter of adjusting the amp frequency/imitation crossover? Do i hook amp up differently to my cd player?

Thank you thank you thank you!!!!!