As I was looking for some information how to deal with my license transfer I found a lot of blogs and forums with not complete or out of date information. The good source to read about it is Beijing Traffic Management Bureau website http://www.bjjtgl.gov.cn/publish/portal1/ there is an english version.
As I read you should go to the main office to get the application form I got lazy and I thought I will send them an email asking for the form. I was really suprised to find the form next morning in my mailbox.
Now it's the payback time, I got an email from them and I promised to pass it to you. If you have some sugestions feel free..

jgj@bjjtgl.gov.cn

Dear Filip ,
This is a email comes from Beijing Traffic Management Bureau. We are going to upgrade our website of English version. In order to provide a convinent
and comprehensive information and service for foreigners in China, we are eager to know your suggestion or advice. Would you please be kindly enough to
sent us your suggestion or advice on the most concerned information or service about Beijin traffic which you wanted most in our new website.
Thank you in advance for any of your suggestion or service.
Best wishes.
Beijing Traffic Management Bureau

I asked them about more info about the registration, plates and insurance and that C3 thing.
I don't know if it's the right place for this thread.

Good contact with the police is very important;)