Thanks for this. Confirmed working on my 1310.
What I did:-
Downloaded file from first post.
Unrar'd file
On Nuvi - open Garmin folder on Nuvi and deleted LEX_PKG file already there.
Copy unrar'd LEX_PKG file to Garmin folder on Nuvi.
Opened Jetmouse Garmin unlocker 1.5, entered Nuvi ID nr, clicked on CUSTOM MAPSET, put a tick in ENABLE ADDITIONAL FIELDS, entered the FID and PID numbers, clicked GENERATE.
Opened NEW TEXT FILE on computer, copy & paste number generated with Jetmouse. Renamed Text File as D046800.unl (Care - in WINDOWS you have to unhide extensions - TOOLS-FOLDER OPTIONS-VIEW-TAKE TICK OUT OF "HIDE EXTENSIONS FOR KNOWN FILE TYPES" otherwise you will have unlock file with properties D046800.unl.txt which will not work.
Copy the D046800.unl to Garmin folder on Nuvi.
Re-hide the file extensions on your computer.
Safely remove the Nuvi from your computer and when you restart it the language guide will open and you'll no longer have the demo version.