Door knock the turbine shops in your area.
Be prepared to prove you can do the work, RAAF qualifications are not taken at face value.
Very few make the transition from RAAF to GA, I left the RAAF 18 years ago and now I am self employed 5 trades Lame so it can be done.
Airline turbine shops are the easiest place for RAAF engine fitters to find a start but only if you can really do the job.
Forget about the advice to go Avionics unless you have time to gain significant experience before leaving.
Good luck