I assume you mean "with pure printing of money, you don't see how to manage the exchange rate".
This is well understood in exchange rate theory. There are three tools, and the one China uses to manipulate the exchange rate is capital controls. A "convertible yuan/renminbi" is worth more than a "non-convertible yuan/renminbi". The effect of high domestic yuan printing, with controlled exchange rates between the convertible yuan and the dollar, is to increase the difference in value between the domestic yuan and the convertible yuan. This has some weird effects, but they're already happening and have been for years. One of them is to drive investment differentially into China rather than abroad. Another is that people will do whatever they can to get their money converted to foreign currency, which has been going on for years, so they'll buy overseas assets when possible.