Default TomTom Edit Map (split, extract...)

Hi,

TomTom 7 with US&CAN Map takes about 1GB on my card, is there a program to edit the map?

I would like to split the US and Canada map in to seperate files (I know it would not work near the border).

So I could use the CAN Map in Canada, US Map in the US and the original US&CAN Map when traveling in between.

THanks,
Galaxy Note (Telus)