Hello, sorry for the slow reply. You would need a copy of the correct apk first, you'll find these with google. Be selective and careful when downloading apks, APKmirror is a good source but always download apks with caution and be aware of the risks, the files can be tampered with of course.

You will have to enable installation from unknown sources in your phone's settings. Google can help you here. After that you can just 'run' the apk file on the phone - easiest to download it using the phone - and it will start the installer.