The phone is running:

SM-G390F

Android version : 7.0
Baseband version: G390FXXU1AQI2
Build number    : NRD90M.G390FXXU1AQI3

Removing factory applications

 $ adb shell
 $ su
 $ mount -o rw,remount /system
 $ rm -R /system/app/application-to-be-removed
 $ rm -R /system/priv-app/application-to-be-removed

file:/system is read-only be default. use mount -o rw,remount /system to make it writable.

Original firmware

Can be found at ​http://live.samsung-updates.com/index.php?device=SM-G390F