First make sure the meta is available for this map.
As mentioned in the 2 Tutorials:
7 simple steps to update your device with the latest map
TUTORIAL: Clean Install - How to install the latest map and navcore from scratch!
Check the Map Thread Finder for maps and meta codes:
As you'll see, the meta code for the map you are trying to use is not available yet, so no matter what you do, you will not be able to activate it.