How to seed data when using Model First approach?

So I am learning MVC3 and EF4. I tried the code first method but it was too confusing for me.. I can create the classes no problem, but the hard part comes when dealing with foreign keys and the relationships between each other.

But I've gone with model first. This way I can visually design it and see where the relationships are.

After my model is create, it creates a SQL for me which I execute against my SQL Express database. Done, and done.

Now I want data in my tables. Of course I can just add them in using server explorer, but most likely I will be making changes to my model as I go along. And keep updating the database. So I can't keep manually entering data. I know if you use code first you can derive the DropCreateDatabaseIfModelChanges and override the seed method.

However how do I do this with model first approach? I have the following code:

 public class DatabaseInitializer : IDatabaseInitializer<BettingContext> {
    public void InitializeDatabase(BettingContext context) {
        var teams = new List<Team> {
            new Team { Name="Toronto Maple Leafs", League="NHL"},
            new Team { Name="Boston Bruins", League="NHL"},
            new Team { Name="Vancouver Canucks", League="NHL"},
            new Team { Name="Nashville Predators", League="NHL"},
            new Team { Name="Montreal Canadiens", League="NHL"},
        };
    }
}

Of course and in my global file:

protected void Application_Start()
{
    Database.SetInitializer<BettingContext>(new DatabaseInitializer());
    AreaRegistration.RegisterAllAreas();

    RegisterGlobalFilters(GlobalFilters.Filters);
    RegisterRoutes(RouteTable.Routes);
}

so now what? How do I tell it to run the method? What am I doing wrong?