I did uninstall EF 6.1.3 and reinstalled 6.2.0

How do I do item 3? The models were created under 6.2.0 EF to start with.

How do I do item 4? Look for what, and update it to what?

Also - I am not using core. I find it difficult to use.

Delete existing code-generation templates.

I'm not using edmx there are no .tt files- I'm using this:

Add the appropriate EF 6.x code generation template. Open your model in the EF Designer, right-click on the design surface and select Add Code Generation Item...
If you are using the DbContext API (recommended) then EF 6.x DbContext Generator will be available under the Data tab.
If you are using the ObjectContext API then you will need to select the Online tab and search for EF 6.x EntityObject Generator.

my model looks like this:

What is a "Design Surface"?

There is no "Data Tab" unless you mean the server explorer.

If you are using the DbContext API (recommended) then EF 6.x DbContext Generator will be available under the Data tab.
If you are using the ObjectContext API then you will need to select the Online tab and search for EF 6.x EntityObject Generator.

Are these in the NuGet Package Manager?

Add C# line using System.Data.Entity.Core.EntityClient; which is the correct for EF6.
As I have said, I am not using Core. I find it cumbersome, frustrating, and counterproductive.

Adding Context:

I'm pretty sure this thing: MvcControllerWithContextScaffolder is what is broken. It's DOWNGRADING EF, and putting the APP into a broken state. I am not sure what or where this thing is, I have been calling it a wizard, or what procedure to use to edit or update it.

The BundleConfig was created in the pre-updated state when I created the MVC project.

Also, shouldn't fully updated VS2019 be... y'know, usable - like when you create a project should it not just work without hunting down mysterious references and doing a thousand fixes?