
INTRODUCTION :
Hello Friends This is so simple process and I try to make most simple, easy and safe guide it. We saw many android phone give low phone memory error and we all want more free space on our Android phone storage for download large size games and install lots of apps. But we can’t do it because of low phone memory (space). In this condition, you can swap your phone storage with an external SD card and resolve your low space problem.
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 Below steps to swap phone storage with your external SD card.
STEPS :
1) You need a rooted phone for this process, if your phone is not rooted then first of all root your phone.
After root your phone, install root file manager. You have two options :
2) Root File Explorer You Can Check it is Paid On Play Store. But Dont Worry I Will Provide You Free Just Go Here And Click On Skip Button

3) 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.

4) 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.

5) 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 /................
6) 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.
Note :
After this process, you will see two files
- vold.fstab
and
- vold.fstab.bak
in the root/system/etc folder. vold.fstab.bak is a backup of your vold.fstab file, if you feel any issue with your phone after this editing, then remove .bak in the name of your backup file and replace with your vold.fstab file.
Now You Done ! Enjoy