In this post, i am gonna show you Android app installation guide and how completely uninstall android apps.
How To Install
->Go to phone settings
-> enable check for Unknown sources
Download APK and install
a. If Data is included: Extract all files from Data to /sdcard/Android/data/
b. If OBB is included: Extract all files from OBB to /sdcard/Android/obb/
See following steps for Install (If the first time or install blocked unknown sources):
Go to Setting then Security
Check Unknown source
Now install your App.
Complete Uninstall Process:
Go to Setting then Apps
Select your Apps that you want to uninstall
Then Clear Data
Make sure that now you uninstalled your app completely with deleting app data.
(In above photos from Andriod 5.0 and You may find differences in other Andriod versions.)