Where exactly in the pairing process are you getting stuck? Here is a help video we made that walks you through the pairing process:
Basically, if you go into your Bluetooth settings, you should see the H9 appear there with its serial number as its name. When you select it, it will ask you for its PIN. The last four digits of its serial number are the default PIN. You can change both the name and the PIN in the stompbox's setting screen though.