What needs to happen, is China needs to get really bored with the N. Korean regime continually preventing China from achieving it's own world goals.
Go back 20 years and China was also isolationist and hard line communist. Now China is going through big changes, it's a hub of world trade, kids are driving around in sports cars and luxury apartments are available for business-people. OK China is still a communist state, but their inclusion as a world trading power means they want to play ball somewhat with the UN and capitalist countries. They are getting slowly embarrassed and frustrated by their support for N. Korea. Once China realise they have no power left over their neighbour, because that neighbour is become so dysfunctional that they can't be controlled, China will allow N. Korea to collapse either with or without the help of other nations. Of course China will want to make sure it gets additional power/control out of N. Koreas implosion.
https://www.cnbc.com/2017/04/11/north-korean-ships-head-home-after-china-orders-coal-returned.html

I think it can get resolved without conflict on an international/global stage, but other world powers need to work with China, the US for example need to stop ratcheting up threats against N. Korea which China will have to oppose. Unfortunately Trumps instability isn't ideal in bringing that about.