Was that the same Chinglish manual that also didn't mention anything about how to adjust the cam pins? I suspect your going to have much better luck asking questions here than reading that manual.
Sounds like you have a set-true style chuck.
This video gives an idea of how to center it starting about the 3 minute 30 second point.
You dont have to do it exactly this guys way. This video is just to give you an idea how it works.
Here:
If you don't loosen the front screws a little first, your going to have an interesting day dialing that chuck in.