In this process, we want a rooted phone which has installed root file manage app like root explorer, ES file manager, etc. I am using root explorer app in this guide, it is a good root file manager app, but it’s paid app, if you don’t want to purchase this app then you can use any free root file manager app. According to my experience this process can’t brick your device. But safe side, you take a backup of your phone, then do it. And first read all steps, if you don’t understand these steps, then don’t do it and tell us your problem via comment, I will try to resolve your issues.
Follow these steps to swap phone storage with your external SD card:
1: We need a rooted phone for this process, if your phone is not rooted then first of all root your phone. You can find your phone root guide of this blog click here. After root your phone, install root file manager. You have two options: 1. Root file explorer app,click here (paid app) 2. Es file explorer file manager, click here (free app)
2: Open the Root explorer app >>> then go to root folder >>> then find and tap on the system folder >>> Now you can see the ETC folder, open this folder >>> after then you will see a list of files and folder, Now find vold.fstab >>> tap on this file, you will get lot's of option, now tap on text editor option. You can see all steps in this image.
3: After tap on the text editor, you will get a popup tab from Su app for giving root permission to root explorer app >>> tap on the grant option >>> then you will get a warning message for remount as read-write then tap on yes. See in this image.
4: Now vold.fstab file open for you, find these two line in this file:
dev_mount sdcard /storage/sdcard0 emmc@fat /............
dev_mount sdcard2 /storage/sdcard1 auto /................
You can see these lines in this image. Not much to do here, just change sdcard0 with sdcard1 in the first line and sdcard1 with sdcard0 in the second line >>> Now tap on the menu button in the phone >>> and tap on save and exit >>> close root file explorer app and reboot your phone or device. that's all.