Replacing america maps with europe fails

I have a nuvi 52 in america bought and I want to install the maps of Europe.
I have already downloaded the europe map also I made all the files visible but he does not work.
Who can help me further?

Did you read this: http://www.navitotal.com/showthread.php?9026-step-by-step-replacing-internal-map-on-nuvi-1xxx-2xxx-and-3xxx ?