If you go to the Automic website (search 'Automic Share Registry' in Google) and create an account / log in, then hit the 'documents and forms' button above the details of your GRB shareholding, then you can download the form..
You can either fill out the form and post it back with a cheque, or just use bPay - details are on the form, and are specific to your form - they identify you from the reference number and the number of shares you want to apply for from the amount you pay...
Then just sit back and wait...
GRB Price at posting:
10.5¢ Sentiment: Buy Disclosure: Held