1 - Clean it - mainly to make sure the barrel/gas tube isn't obstructed with grease or foreign debris.
2 - Lubricate with oil/grease of choice.
3 - Shoot.
4 - Repeat step 3.
Really no break-in required. Things will get smoother with use, but there is no specific format I'd use. Don't shoot it mag dump after dump until it glows red - but other than that, let'r rip.