Uninstall Guitar Pro 6.
Download the Full version of Guitar Pro 6 and install it. Run the GP6's updater once installed.
Guitar Pro 6 Fretlight Ready Full and RSE download links:
Install this full version of the GP6 program when the download is complete.
Start GP6 and launch the updater from the "Help" drop down menu on a PC and from the "Guitar Pro" drop down menu on a Mac.
You may need to run the updater several times to get all of the available updates.