First you need to have your HIN or SRN. I can get my HIN from my portfolio holding in Commsec.
HIN starts with either X or I and 10 digit numbers (add 0 or 00 after X or I if you get only 9 or 8 digit number).
Go to https://www.investorvote.com.au
The Control number is 133122 or 183122
Good luck.