Before you can sideload applications on your Android, you will have to download the ‘APK’ files, either on your computer or directly on your phone. APK files are installation packages and can be found on the internet for apps which are not available on the Play Store or for apps which you or your friends develop for testing.
If you download the packages on your personal computer, you will have to transfer them to your device by connecting the two. You can use the USB cable that came with the device and connect your phone to your computer and transfer the downloaded files to your device’s internal memory.
Once you have copied the files to your device, or in case you downloaded them directly, you will need to access them and install them. However, before you can do that, you will need to enable installation from ‘unknown sources’ in your device’s settings.
Go to your settings page and scroll down to open up the ‘security’ options. Now scroll down until you find the ‘Device Administrators’ section, under which you will see the ‘Unknown sources’ option. Tap on this option to check it and exit the settings page.
Now you will need to run your file manager application (or download one for free from the Play Store) and navigate to the directory where you copied or downloaded the installation packages. Once you locate them, just tap on them to run them and follow the on-screen prompts for successful installation.