1. In your Ableton project window, click the button marked in red below to open the Library.
2. Click on Drums then drag and drop the Drum Rack to a space at the bottom of your screen.
3. Tap and hold a pad on your MPK Mini down, you will see a yellow block appear to the side of the drum rack.
4. Click on that yellow dot, then tap and hold your pad again to reveal the exact drum rack block which corresponds to your pad; it will be marked with a yellow play icon.
5. Now that we have found the drum rack block that corresponds to your pad, we need to assign a sample to it.
Click Samples from the Library, then drag and drop your desired sample to the pad which was marked with a yellow play icon in step 4.
6. Strike the pad and you will hear the sample being triggered.
Follow steps 3 - 5 again for all of your pads to continue assigning samples to them.