Step 1: Install Android File Transfer on your Mac computer (OS X 10.5 or later). This application will let you transfer files between your Mac and your Android device (Android 3.0 or later).
Step 2: Enable USB Mass Storage mode on your Android. To do so, go to Settings > More (under Wireless and network) > USB utilities > Set USB cable connection mode. Then, select “Connect storage to PC.”
Step 3: At this point, you will be prompted to “Connect your USB cable to use mass storage.” Using the USB cable that came with your Android device, connect your device to your Mac.
Step 4: Now that your devices are connected, double-click Android File Transfer on your Mac to open it.
Step 5: Using Finder on your Mac, navigate to your Android device, which will be on your desktop. Open another Finder window anywhere on your Mac — most likely your Music folder, for the purpose of this tutorial. Now, you can drag-and-drop to files from one device to the other, copy-and-paste them, or whatever else you want. You can also delete files from your Android to make room for more stuff.
I learn how to do it in this guide, you can take a look.
How to Transfer Music from Mac to Android