This is what I found in the NAV FAQ article under Navigation Section. Are you sure you were looking at the right article? If you scroll almost to the end of the article, you'll find it

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To upgrade your navigation software, follow these steps (see http://www.bimmernav.com/software.htm for additional tips)

1. Go to your vehicle and turn the ignition switch to the first position. Let the navigation system boot up and get into a normal operating mode.
2. Leaving the system on (never turn the power off during these steps!!), go back and eject the navigation CD from your drive unit.
3. Put in the V "XX" disk into your drive unit. Watch your screen and be patient. It will take about 6 minutes to do the upgrade. When it’s done it will eject the CD automatically. (note: for MKIII systems that are on version 17 or lower, the system may ask you to insert the Key CD. If so, insert the KeyCD and then follow the on-screen instructions. THIS ONLY APPLIES TO THE MKIII)
4. Put your navigation CD back in the drive and make sure everything is working properly.

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