Australia's Coins - What happens now?

On Friday, at the Start of this weekend, we all received the incredibly sad news of Queen Elizabeth the 2nd’s passing.
As the Queen of Australia and Her other Realms and Territories she spent over 70 years on the throne and she leaves an incredible legacy behind for all of the subjects of her Commonwealth countries.

And now that Royal proclamation’s have been made in both the UK and Australia
King Charles the 3rd takes the throne as King.

But I'm being asked by my friends, family and my viewers on YouTube about just what does this mean for our coins and banknotes.

Will they be changed or withdrawn, will we have to exchange all coins with Elizabeth on them for new coins? Will existing coins become more valuable?
and when can we expect to see king Charles iii face appear on our currency