Basically, you should buy a Garmin GPS Reciever and the software provided together to use Garmin products.
STEP ONE: First thing to do is to get Garmin Mobile XT software for your device. Go to Garmin Mobile XT website, and download the right version for your phone.
Once you downloaded the installation files, connect your phone on the USB DATA TRANSFER mode and run the downloaded file. The installation program will ask you where you want to install Garmin Mobile XT? Just choose the right drive (your phone) and click on “Install”.
STEP TWO: Get the Support files (from the bottom of the same page ) and install them in the same way on your phone.
STEP TREE: Get the map you need and copy the map IMG file in your phone’s memory card, inside the “Garmin” directory.
On the next page(s) we’ll see how to activate the internal GPS support for Garmin on your mobile phone…