Intall on Garmin G5

I want to replace my (broken) electric turn a bank indicator with a Garmin G5. So there is a installation kit ($50) that looks like it has a panel bracket and some connectors. The unit comes with or without the wiring harness (4'). What is involved in installation. Looks like at the minimum I have to T into pitot to get airspeed and keep my existing airspeed indicator. I think I will get the backup battery.

Airplane is '67 Citabria 7KCAB with just basic instruments.

Your airplane is on the STC, you need an A&P to do the install and an IA to approve the return to service on a 337 form. Alternately a repair station could also do the install and paper work.