Neutral Safety Switch, where is it located, and what are the steps to repair/replace?

Hi. My neighbor ran a code scanner on my vehicle listed above Titanium and said my neutral Safety Switch is bad. I believe from my research that my car has the transmission range selector instead, but I need to know if it is outside or inside the transmission. And what are the steps to repair/replace please and thank you. This will determine if I'm able to have it fixed at home by my bf/sent to shop or junk it. Thank you.