I am unsure of which is the correct procedure to follow with my Navigon unit, it is labelled as GARMIN on the front, doing some digging around within the files on the unit I have the following from the version.xml file
<software>
<version>7.16.9</version>
<build>314</build>
<brand>NAVIGON_EU</brand>
<platform>SKODA_PID_V2</platform>
<copyright>Garmin W&#x00FC;rzburg GmbH, Copyright (c) 2014</copyright>
<productprefix>N7</productprefix>
<style>SKODA</style>
<productid>N7NFRC8CNZEXS5K</productid>
<id>TMBZZZAAZFD636961</id>
<romimage>
<version>2.33</version>
</romimage>
<bluetooth>
<core>
<version>1.1.102.105</version>
</core>
<firmware>
<version>H14423-V2R43</version>
</firmware>
</bluetooth>
<gts>36|4|12|7|7|115|5|218</gts>
<expirationdate>20171020133251Z</expirationdate>
</software>

It appears to have a fairly small internal memory at just under 4 Gig and I have done a back up of all files from the unit to my computer, this has been done with a back-up utility (Linux) and a straight copy of all files including hidden to my hard disk.

It is fitted into a 2015 Skoda Citigo.

Looking at the list of software on the first post I do not see the version or build numbers so I thought I had better check check before I ventured further and trash the unit.

Cheers

Adrian