I recently joined TPG. I am currently with Telstra Broadband. I have received the modem and the the NBN connection device. At the moment I am still with Telstra untill I am connected to the NBN. However I keep on getting messages from TPG " Action required. Your TPG service is awaiting activation , please connect your NBN modem as soon as possible. However I have never been connected to the NBN yet.
Sounds like you're ready for "self-install". If you have FTTC, just follow the guide you would have been sent with the NBN modem. What type of NBN do you have? (FTTP, FTTC, FTTN, HFC etc)
If you're not sure, Google "NBN Map"