I was very well able to DoW ming on day 1 and totally roflstomp them. Just need a decent general with at least 2 shock for that. After that, you get all the provinces you need for Qing, wait until you have mil tech about 8, and do "Tribename" -> Qing straight away. And with the current state of things, Ming will most probably die to rebels with countries forming here and there, and have ~100% autonomy on most of its provinces, so you will be able to vassalize it in one war. Was able to do it on my Tibet run before with ease.