Transit at Shanghai Pudong Airport for 12 hours, Singaporean passport holders

Thanks for your reply for my previous queries.
I have changed my flight schedule (China Eastern Airline) to : Singapore to Shanghai Pudong airport (transit), then to Seoul (final destination).
1) I am holding Singapore passport, do I need to apply for the temporary stay permit if I want to leave Shanghai Pudong airport to downtown for sightseeing (transit around 12 hours)?
2) if I need, pls kindly advise where and what are the procedures to apply for the temporary stay permit.
Thank you