Simply download this file, unzip it and put it onto a clean SD Card. If you use an HDS then the file can go anywhere on the card, although you really don't need this test !
If you use a Pre HDS GPS such as the 5300c or Elite 5 etc then you must put the file into a folder called "Maps0". you then need to pan to the position you see in the picture below. The chart is constructed using the most compatible colours, and Atlas V6.