Nicole has a cellphone and was running Google Voice. She wasn't too thrilled with it so she cancelled her Google Voice account, but it's still active and friends can't leave a voicemail now. Leo says that a setting in the carrier's voicemail settings will fix that. She should install the Google Voice app on her phone and then turn it off.
According to the chatroom - dialing *73 or *730 will turn off call forwarding. If that doesn't work, she can call her carrier and ask them to restore her regular voicemail.