How do I use Nuendo plug-in set in Cubase?

I bought Nuendo last year on sale and now want to stay on Cubase since it now has everything I need and is always ahead of Nuendo. The extra Nuendo plugins are not showing up in Cubase though – where do I find the Nuendo plug-in set (a single VST3 file, if I remember correctly) and where do I move it to work in Cubase? I tried the regular VST3 folder but the plug-ins don’t show up in Cubase.

You dont. They are most likely linked to the nuendo binary as most stock plugins are. So they do not exist as .dll or .so files. Over the years there have been some exceptions, I guess the exceptions were plugins bought from other vendors.