Here's what will happen:
1. You will first receive an SMS to inform you that the installer is on his way.
2. The installer will meet you to explain the installation process. This includes signing the rate card (agreement to any extra charges ie: additional wire length to be laid). If your unit comes pre-built with a standard fibre port, you can skip this step!
3. The installation will only start when the rate card is signed by both you and the installer.
4. The installer will then pull the fibre cable from the riser up to your unit and to the router.
5. Finally, the installer will run a speed test to ensure that the installation has been done properly.
We've got a great video about the installation process here.