Anyone has an up to date Android tutorial?

[JackyBorderCollie]

Basically title. I want to make a GDPS on Android, however, I cannot seem to get it to work. Hex Editor doesn't work for me, it doesn't want to edit the file. When I try to edit it, it just says "read only mode enabled" or something like that. Can someone provide me an up-to-date tutorial on making a GDPS for Android?
Android version is Android 12