Just finished getting Manchurian Candidate achievement (plus Turn the Tide), and AI Ming is a mess. I started as Jiangzhou and managed to DOW one of my neighbors before Ming warned me. As the war went on, another AI declared on the same neighbor, so I vassalized both of them. Meanwhile, rebels had some fun with Ming. Miao and Dali broke free, and Ming burned their troops/manpower fighting peasants. Oirat DOWed a few months before this first rebel wave and called me in. They dragged the war to 95%, freed Xi and took some land (and gave me a couple of provinces). Then, more rebels spawned, including Manchu patriots. The patriots defected to me, and I was off to beat on Korea. I then annexed my Manchu vassals and vassalized Koshin. A second war against Ming got me Beijing plus a few coastal provinces in Canton. I freed Zhou, and DOWed Mongolia (still Oirat's vassal) for Xilin Gol. This was the bloodiest war I had to fight to get the land I needed. Mongolia is all wide open, so even with better generals/tech/morale advisor, I took heavy losses from Oirat+friends.
During all these wars, all Ming could do was wait for rebels to break the country, then build 4-5 units and get swarmed by rebels again. They went bankrupt twice, every nation that could split off them did so (except for Zhou and Shun, which I eventually created as a vassal too).
One thing that I did wrong the first time was trying to form Manchu before having the land to form Qing. By doing that, you lose the +50% manpower/FL horde bonus, but remain in the Steppe tech group. It's better to stay as a tribe until you take Beijing & Xilin Gol. Then you can go Tribe > Manchu > Qing immediately.
To get Turn the Tide I took Exploration as my first idea (before all the fighting above) and wormed my way to America. I met France just South of the Mexican tribes, and westernized off them (or maybe Portugal, who also colonized next to me while I waited for my colony to finish - forgot to check who had more tech when I started westernizing).