change all the RMB you need (and alittle more just in case) in HK. moneychangers
are everywhere in HK and all will gladly accept your AUD and HKD for exchange
to RMB. in the case of your AUD, they will convert the AUD to HKD at the prevailing
rate before converting it to RMB at the HKD-RMB rate.
not impossible to change money in china especially in a big city like guangzhou however,
this is a really pain-in-the-neck process. on the mainland, only bank of china branches
are allowed to do forex exchange and it is one heck of a tedious process lined with
paperwork. you will need your passport to change even the smallest amount of your
foreign currency to RMB.
note: there are no private moneychanging booths/shops in china. thus, anyone who offers
to change money for you is most definitely a blackmarketeer who is more than eager
to push his load of counterfeit RMBs to you at a highly disadvantangeous rate.
change it all in HK!