How to apply custom Samsung themes on Android Pie 9

1. Download the APK theme file
2. Install One UI theme installer on playstore.
3. Open the app and install the APK
4. Then open the custom one ui apk that you have installed, follow steps 1 to 3 until you see the sign “✔”
5. Finally click the install theme option
6. If the screen is already on, it will redirect you to the home of the galaxy theme, then apply the theme that you have installed through one ui.

If there are some parts that have not been applied, restart your phone until every part has been applied.

P.S :
-One UI theme Installer allows you to apply the theme permanently.
-The lockscreen wallpaper is black so you have to install it manually in the app by choosing ” apply lockscreen wallpaper”.
-Whenever you want to switch themes, uninstall the old one.