How can an adult and two children become part of an audience in channel 7 in school holidays?

How can an adult and two children become part of an audience in channel 7 in school holidays?
You first have to contact Channel 10 because they are interlinked. They will then pass on the message to channel 7. If they refuse to talk to you, you have to tell them the codeword 'Jumpsuit'. To participate in an audience is free on Wednesdays.Hope this helps!