You can use this tutorial :
I choose to do it in an android VM because I don't trust the application used. But you can do exactly the same in your Android Phone.
The idea is simple : Fake your GPS position, and hide it to Pokemon Go. Use a VPN also to download the maps from google.
I am level 9 so far, playing in Disneyland Los Angeles with a fake location. It's less fun than playing the real game, but it allows me to get a lot of pokemon and be ready when the games arrives in China.
Another solution is to move to north China (Neimeng, Heilongjiang ...) and use a VPN. The GPS position is not blocked in the north of China.
For information : I'm team Blue ! Go Mystic !