Why on earth would you need to change the frequency being used on your phone? If you need to use it in another country, any dual/tri/quad band phone sold in Canada will automatically change frequencies when required (usually when travelling in another country).
You can set it manually using the method you copied from the other site. The 'engineering model' is the screen you enter when you enter the number after going to the menu.
Hope this answers your questions, and is the last time you're seen on this site.