I have a TomTom One/XL (30-series). It came with Western & Central Europe installed. The maps are three updates out-of-date. Rather than update the entire map (I only use the Ireland map) I've downloaded the latest United Kingdom & Republic of Ireland map which is only about 131 mb. I'm wondering how I can switch my device to only using the new United Kingdom & Republic of Ireland map rather than the outdated one contained in the Western & Central Europe original map? Thank you. 