goto
http://www.prometric.com.cn/aptcquery.asp?page_id=84 check the exam sites
and there are 5 of them, choose one near your place and call them, tell them you want to take SUN 311-110, with free electronic voucher,
and your prometric ID, they will register for you, and ask you to print the email of the voucher.
they said I could go there between 9am - 3pm.
Good luck
SCJP,SCWCD,SCMAD,OCP9I, SCEA