Problem:

You have an issue with Android Studio and want to reinstall it. In order to reinstall a fresh instance you need to uninstall the current version first.

Solution:

Execute these commands from the terminal:

rm -Rf /Applications/Android\ Studio.app
rm -Rf ~/Library/Preferences/AndroidStudio*
rm ~/Library/Preferences/com.google.android.studio.plist
rm -Rf ~/Library/Application\ Support/AndroidStudio*
rm -Rf ~/Library/Logs/AndroidStudio*
rm -Rf ~/Library/Caches/AndroidStudio*
rm -Rf ~/.AndroidStudio*

if you would like to delete all projects:

rm -Rf ~/AndroidStudioProjects

to remove gradle related files (caches & wrapper)

rm -Rf ~/.gradle

use the below command to delete all Android Virtual Devices(AVDs) and *.keystore. note: this folder is used by others Android IDE as well, so if you still using other IDE you may not want to delete this folder)

rm -Rf ~/.android

to delete Android SDK tools

rm -Rf ~/Library/Android*

Source: http://stackoverflow.com