please help me and share it

my I-485 case was approved on May 2005(fee already paid in US),it was based on my wife's employment_based adjustment in US.I am currentlly living in China,How to get the stamp done and how much does it cost at the US Consulate in Guangzhou( pay $380 or more )? what's the procedure for me to have it done in Consulate in Guangzhou? if not,
can i back to US by using advance parole travel document.please help me !!!
Thanks lot