-Run an RCA to 3.5mm cable from the record out on your mixer to the 3.5mm port on your MacBook. -Set 3.5mm port on MacBook to force as a line in (system preferences -> sound) -open audacity (get it if you don't have it), choose your soundcard as input device. Hit record in audacity and set your gains so they don't clip, then you're sweet. Hope this helps