Easiest way to field strip is use a metric allen wrench and unscrew the spindle bolt on the rear of receiver. Be careful not to loose or strip it as they are impossible to find. Once the spindle bolt is out, the receiver will slide off. At the rear of the receiver is the buffer. Remove the buffer and the retaining clamp for the buffer. Once the buffer is removed, use a long flat blade screw driver and push in the knob at the rear of the bolt carrier. I think it is the firing pin button(can't recall). When you depress this knob on the carrier, the carrier along with the bolt head will come out. You can then take this apart and clean it. Once you have done this a couple of times, it is easy, but th first time can be a challenge.