Change Currency symbol

Change Currency symbol

I would like to change the way our currency displays when printed on quotes, invoices and purchase orders. 

Currently, we have Australian Dollars AUD as our Home Currency.
 
The only two symbol choices available for this currency are "AU $" or "AUD". 
I would like to be able to just have "$" as the symbol, so that the AU or AUD bit does not print on our invoices, quotes etc. 

As we only operate in Australian Dollars, it is confusing and just looks silly to have this on our invoices. 

Are you able to add the option for "$" as a symbol for AUD, or is there some other formula or workaround that I can use to achieve this? 

Thank you, 
Bianca. 

    Nederlandse Hulpbronnen