how to uninstall android device manager to samsung SM G900S.
how to remove applications under administrator.
Unless the phone is rooted, you cant typically remove apps that are labeled system apps. You can try disable them, preventing them from running. And some apps that are labeled as system apps cant even be disabled.
But anyways to check and see if you can remove them. Settings > App Manager, then scroll til you find Android Device Manager. Press on it. See if it will let you uninstall it or disable it. If you cant uninstall/disable it. You will have to root the device to remove it.
If you are rooted, You might still need a 3rd party app to remove the app. Such as Titanium Backup, which can be found in the play store. Then that will allow you to freeze/disable the app, back up the app, or fully uninstall it.
Edit If you are rooted, When you are wanting to remove apps and if they were system apps. I would suggest freezing or making a back up of the app just in case the phone starts acting up. That way you can reinstall them without having to go hunt for the apk. Cause some apps rely on each other to function right. Especially when dealing with Samsung/Touch Wiz.