How to execute EF5 savechanges from a derived BindingNavigator class

How to execute EF5 savechanges from a derived BindingNavigator class

I've created a cutom BindingNavigator with custom ToolStripButton(s),
basically working with datasets, in which I've coded delegate actions to
perform when adding, deleting and updating records. As I'm moving to EF5,
I would like to make the same thing, the idea still the same, but when
executing these three methods:
this.BindingSource.AddNew();
this.BindingSource.RemoveCurrent();
this.BindingSource.Update();
modifications are made in runtime but not in database.
I found later that i must execute context.SaveChanges();
to make data concrete.
Can anyone help on how to call the context from the custom binding
navigator class.