Basically, You cannot delete an OS of Android Smartphone. OS is basic necessity to run hardware to it’s specified programs. Without an OS the smartphone is nothing but just a bunch of hardware which is useless. Yet, You can replace the Stock OS to any other custom rom just in case to get peak performance or any more.

Can I change OS of Android?

Android licensing gives user benefits of accessing free content. Android is highly customizable and excellent if you want to multitask. It is the home to millions of applications. However, you can change it if you want to replace it with an operating system of your choice but not iOS.

How do I uninstall and reinstall Android OS?

To reinstall Android OS with or without PC, first of all, go to Google and type for custom ROMs available for your phone model and download them to your SD card. And then switch off your Android phone. And go to custom recovery mode by pressing the volume up or down button and the power button simultaneously.