Activate Windows Defender?

Norton Security is enabled on my laptop. But soon my free trial version will expire and I would like to use Windows Defender. How can I activate it then? In the settings this does not work for me because Norton Security is activated.

Norton Delete.

As soon as Norton Security is uninstalled, the Defender reappears with its options. I would possibly even uninstall it with the appropriate Norton tool, because if there are leftovers the Defender still can't function properly.
https://support.norton.com/sp/de/de/home/current/solutions/v60392881

Can I really delete Norton completely, even if it was preinstalled?

On their homepage there's a Deinstalationstool remove completely everything.

Why anything extra at all:?

Windows Defender is completely sufficient and if you have a brain that thinks 30% with each download, nothing usually happens.

No front to other AV programs but most, not all, tend to give attack opportunities or worsen the security of the device.

So if you should uninstall norten, Windows Defender would have to take over again after a restart. It probably says blablabla antivirus is used to defender, right?

So the very long text very briefly when Norton is gone, the Defender would have to run again the next time you restart