How to programatically navigate from one page to another?

[gmgallo]

In a MVVM template project I'm trying to navigate from one page to another programmatically, for example when the user must update a setting in another page before continuing. The idea behind is that there is only one place where settings must be changed and saved.
I know that NavigationService and NavigationHelper are the way to go, but I can't figure out the right way to use them in code.

[tinmac]

To navigate from Pae to Page in code you would do something like this

this.Frame.Navigate(typeof(Main_Page));

The above example resides in a Login Page code behind