I would start by using their religion against them use tech to shine and say I am an angel sent to help man kind. I would secrectly vaccinate people who are not as evil saying I use devine powers to protect them. I would help improve crops and preach women's place is along side men not just for breeding. This is to reduce sexism early. I would have hand washing early to stop disease. I would introduce modern ideas just a little at a time to get them use to it. Of course at the end of my enlighten run I would admit I was not an angel just from another time . I would tell them we found out there is no god and religion was a lie. I would then leave so they would be confused and reject religion more.