Go to the TomTom Maps thread on the Forum main page. The stickys on the main TomTom page will guide you till the end.
On a side note (due to not being able to create a new post) Does anyone know why after I patched the Navcore and activated the map (920.5267 & navcore 8.010) my screen is far to the right? Tried wiping the GPS and starting over twice with no resluts. Works fine if I plug it into the computer turn it on and then disconnect it, but if I turn it off and back on it's messed up again. Had no issues with previou map updates I have done with the same steps.