Check this for instructions and link to github download. For settings, you will pick G5.
I think Transmitter will not pair/connect with phones if g5 app is active, so if have g5 app on phone may need to uninastall and reinstall after reset. But you may find you like xdrip better.
May want to just try xdrip before reset, since with G5 dexcom transmitter will continue to read even without reset.