Personally I think the only way is if the Chinese government get their shit together and invades/starts war with North Korea. By that, not only an international movement will be started to help defeat the Kim regime, but it will show a lot of North Koreans that: 1. North Korea really isn't the big badass nation it states itself to be. 2. The Chinese aren't their best friend, and that they shouldn't kiss their ass. 3. They aren't impervious to outside threats. 4. It will give those who want to destroy the NK government a chance.

I mean, imagine if China started the war. If they freed those in the death and labor camps, their ranks would be massive! Sure there would need to be a huge amount of rehabilitation but once they can stand on their feat and handle a Type-56 there would be an immeasurable amount of people who would want to destroy the NK government for doing what they did to them and subsequently the next 3 generations of their families.

Couple that with gargantuan amounts of Pro-Chinese and Pro-Democratic propaganda and you have a sure fire way to make sure the hermit kingdom will erupt in the revolutionary fires of civil war. Not saying war is good, but asking Kim Jong Un to step down is probably not going to work.

Not to mention, if China attacks South Korea is going to have to act fast and attack as well. Once that happens the United States is pulled in. Then possibly NATO and the EU. Like dominoes, things will fall in place and all it takes is for China to toe that line, tease North Korea and then push into their shit really hard.

Oh and I know about all the emplacements ready to blow South Korea to hell if someone were to invade, but hopefully China would tell SK what their plan is, and the South Koreans will evacuate their innocent civilians.

And don't worry about nukes. All those rockets blowing up mid air might be the US using their anti missile laser defense weapons systems. Even if its not, great news is still great news.