Safaricom and Verizon GS6

[AC Question]

So i travel to Kenya for about a month every year as a travel EMT. Last year when I was there, I popped a safaricom sim card into my phone. It didn't work right off the bat , but after stopped at a Safaricom store, they were able to access a screen under network settings and change some things and get the phone to work. Took the girl about 2 minutes and everything was fine. I had to replace the phone a few months later when the battery started to crap out on me. I foolishly forgot to take a screenshot of the settings. I have seen forums on the web with all the changes listed but for some reason i cannot find them now. Does anybody know what I am talking about and how to do it?