Not sure how easily common people would overthrow him. It's a firmly closed, deeply repressive and technologically backward regime. This won't be like East Germany or Poland, where ordinary citizens end the ruling regime by democratic protests. The likes of China, South Korea and Russia are the keys to any regime change there. I recently read a book about the history of North Korea that notes the regime has always ran on a bizarre notion of self-proclaimed self-sufficiency, which was anything but, since it largely entailed playing friendly countries (China, USSR, East Germany) off each other in order to extract more benefits for the regime.