What is the best way to install NS?

Hello everyone,

After over 10 years I am using NIS, I'm now considering to buy NS (5 devices) and I wanted to ask what is the best way to install it, through an over the top install letting NS take care to uninstall NIS or is it better to use NRT for the removal.

If an over-the-top installation was the best choice, data such as the Personal Firewall settings will be preserved?
I am not concerned to preserve the ID Safe data since I don't use this feature.

Thanks in advance for any suggestions.