How to uninstall System Apps from Android Device

A new device comes with many pre-installed apps, many of them we never use. These apps just eat our system memory and battery. So its better to uninstall them.
To uninstall a system app, first you need to root your device. If your device is not rooted then its not for you. For Un-rooted device you can just go to Settings>Apps>Select App and just disable it.
If Your device is rooted then download Link2SD app from play store. its available for free. You can uninstall your system apps using this app. Apart from this you can convert any user app to System app, integrate update into system and freeze system app. So install it and get rid of unwanted system apps.