Credits to Princeton Miel Jurilla! :y:
How to Unroot Any Android Device
Before anything else, backup your ROM first just to be safe.
• Backup using CWM recovery
• Backup using TWRP
Manually Unroot Any Android Device
1. Download and install any file explorer/manager on your device which is capable of accessing the root system. For those who doesn't have one, you can download ES File Explorer which is free downloadable app from Google Play Store.
2. Open ES File Explorer or any similar app.
3. From the ES File Explorer or any similar app, tap on the slash symbol "/", but if you are using Root Exlorer, tap on the plus button "+" below and select Root tab or something like that. If it asks you for root access, grant it.
Now we need to delete the su file from bin or xbin folder.
4. Now, go to System > Bin > folder and find the su file, if there's any, delete it. If there's none, proceed to step 5.
5. Go back to System folder and open the Xbin folder. Find the su file and delete it.
6. Navigate back to System folder and delete the superuser app you are using. Delete either Superuser.apk or SuperSU.apk.
Unroot Any Android Device with SuperSU
1. Open SuperSU app from your phone's app drawer or app list.
2. Navigate to Settings tab.
3. Find and select Full unroot.
4. Let the app to process your request. Done!
Unrooting Any Android Device using Framaroot
If you have used Framaroot to root your android device, you can use it too for unrooting it. This works especially when you have Qualcomm, MTK-based android device, etc..
1. Download and install Framaroot in your android device.
2. Select Unroot.
3. Click Boromir for MTK-based, Gandalf for Qualcomm-based, Aragorn for Samsung.