Playing music from your computer through the mounted speakers

[ARMYOFME]

Hi Airstream Geniuses!

So we have a 2005 International CCD (22') and right now it has a nice 4 speaker system mounted in the overhead cupboards, very low profile. There's also a mounted stereo headplate that has the flip face and you can slide CDs in it and they play beautifully. Unfortunately, we're trying not to bring CDs and would much rather play music from our Mac and have it play through the speakers. I know I can bring portable speakers and set them on the table or whatever but I would rather do something way sexier than that and play through the existing speakers.

Any brilliant ideas for how to do this???

Thanks in advance!