Hi Mr. Shephard and thank you for your patience. My name is ***** ***** I will be happy to assist you. From what I understand, you would like to update your current maps and purchase a map set for England and Wales in the UK.
First let me ask, some nuvi 50 models come with lifetime maps. This is indicated by "LM" suffixing the device model for example your box would have read Garmin Nuvi 50LM. Do you have an LM model or a regular model?
Ok great. To purchase and perform a map update for the maps installed on your device, you will need to download and install garmin express, software which enables you to update your device. You can download it by clicking here.
Once you have it downloaded and installed, run the program. Connect your device to your computer and turn it on. Then follow the prompts on your screen from Garmin Express. Once the device is properly added, select it and it will scan your device for required updates. If an update is available for your map it will prompt you along with an option to purchase the updated map set.
Now to add the additional maps, I recommend purchasing them on a microSD/SD card. The map size for the UK is fairly large and your device is only capable of holding so much data. You have several options for this. One, you can purchase it from a Garmin retailer and most electronics stores that carry Garmin will carry the maps. Second, you can purchase it from the Garmin website and have it shipped to you. Lastly, if you have a microSD/SD card available, you can purchase and download it directly from the Garmin.
To purchase it directly from Garmin, you can find the purchase page by clicking here.
Once purchased, if you choose download you will be taken to a page with instructions to download the map set. If you chose to purchase the microsd/SD card, once you receive it in the mail, simply insert it into your device and you will be able to use the maps.
If you have any questions about the information I provided please let me know. I will be glad to answer any follow up questions you may have.