If you are released from your contract by the club, you’ll probably want to find your way back into management as soon as you can. The same Job Security screen lists all available jobs which you may apply for by selecting the club and then clicking ‘Apply for Job’ from the ‘Actions’. These jobs will also appear on your Managerial Overview screen for the duration of your unemployment.
I got that from the FM Manual. But even with the vacant jobs I can't see where it is that I apply?