First, you need to enable the installation of apps from unknown sources. To do this, go to Settings > Security and enable the "Unknown sources" option.

Download the Google Camera APK file from a trusted source. You can search for "Google Camera APK" on your favorite search engine and download it from a reliable website like GCamapk.pro.

Once the download is complete, locate the APK file and tap on it to begin the installation process.

Follow the on-screen instructions to complete the installation. After the installation is complete, tap on "Open" to launch the app.

Grant the necessary permissions when prompted to do so, and then start using the Google Camera app.

All done!