Rental bond recovery in case of breaking shared lease agreement

I took the lease of a two bedroom apartment with my friend in docklands victoria, we lived together for 1 year and the lease was renewed for another year this august. But due to some personal issue things are not working out anymore and I want to move out from the apartment. How can I recover the bond amount(3000$ 1500$ each) which we paid jointly to the rent agency(which submitted it to the RTBA). I know we can either terminate the lease, or I can move out and get another person to sign the lease agreement, in that case I will bear the lease name change fees charged by the agency, but I don’t know what is the process in these situations, will the agency/RTBA be returning the amount in my bank account, or will I have to ask the new guy to pay me the amount. Will the agency lodge a new bond with RTBA? I do not know of the process. If somebody who knows it could tell me, I will truly appreciate it.

Thanks a lot in advance.