GO to any bank with your PP each day and exchange a little at a time. I think you can do 3,000 a day, maybe 5,000. Is you start today, you will have it all exchanged by Friday. You can exchange any remaining you have at the airport when you get there. Pretty simple actually
If that does not work, you can go to any 5 Star hotel and they have automated machines you can exchange RMB for USA, again, I think it’s 3,000 or 5,000 a day. The machines are in most of the major Branded hotels.
Depending on your location, some are easier to find than others.
If you are near Nanjing Road, I know for sure they have one at the JC Mandarin
(across from plaza 66)