Reg. Framework 4.5.2 update

Hi,

We have web application compiled using .NET framework 4.5. Application is running fine in the production. However, since support ended from MS(https://blogs.msdn.microsoft.com/dotnet/2015/12/09/support-ending-for-the-net-framework-4-4-5-and-4-5-1/) for 4.5, we need to install 4.5.2 on the server. As I understand everything will work fine after 4.5.2 install.

Question is- what is recommended approach?-, do I need to uninstall 4.5 and then install 4.5.2 on top of the 4.0 base framework? Or just installing 4.5.2 on top of the current 4.5?

Also, since the link above says all three versions (4,4.5 and 4.5.1) support is ended, what is the base version which is supported by MS on top of which 4.5.2 runs?

Thanks,

Ram