We can no more tell the Chinese to change their exchange rate than we can tell them how to run their military.
Clear misunderstanding on exchange rates. They can’t be set. The way that China offsets their trade surplus with the US is by buying US dollar denominated securities (treasuries and stocks). This creates a damned if you do, damned if you don’t scenario. The treasury purchases that China does to offset their trade surplus is helping the Fed keep their lending rates low.