If you are going to edit the json file then use this to edit it: https://jsonformatter.curiousconcept.com/
• a program to rename • tex3ds[1] (Coming soon!)
First Download the source code, then Extract it. Then rename the .json file from "store.json" to "emustore.unistore" Then move it to, sdmc:/3ds universal-db/stores/. Use it by going into Universal-Updater then going to settings/Select Unistore then pick emustore.unistore
Follow the steps on post #4 from here https://gbatemp.net/threads/how-to-use-tex3ds.629212/#post-10110549