Step 1 - If you installed the 3.0 x series disk image it has to be reverted to 2.006 or earlier for it to work.
Step 2 - sd card 1 will update your unit from 2.006 to 2.1
step 3 - unit restarts - after unit is running place the sd card 2 in unit and it automatically strats, it will give device id and let you know password will be required. You need to type the password in a screen that shows all **, which is lame. then the update starts for map updates, it takes 45 mins at least
step 4 - unit asks if you want to keep your splash screen etc, then updates the unit from 2.1 to 3.02 as a normal firmware update.
It took me an hour and 10 minutes to do the update if you have to revert to 2.006 prior to starting the update, it will NOT work going directly from the x series image on your drive.
This is not a step by step guide as much as it is a general what to expect when updating. I know I missed a few steps and details. If someone can help me out with the nitty griddy details I will be happy to update this guide.