I did my own upgrade to -10, -11, and -13.  Just follow the menu structure in order, and press the save config softkey after each menu page load completes.  It will take about 2-3 hours, so have ground power connected.  There should be a document on your garmin FTP site that has the instructions.  Don’t skip any steps.

Make sure to restore your fuel tank calibration settings.

I put together a cheat sheet that lists all of my specific settings (such as cable DB losses, fuel flow factors, etc.) so you will be sure to change them during the update.  I would share it, but it is very specific to my setup that it won’t do you any good.