Hi Utta,
I fear that it will be your task to move all the buildings, that is,
for each building remove the georeferencing information, then import
the terrain again, move the building so it fits onto the terrain,
check in GE and, if OK, re-upload the model using the same model ID.
If you need more details on this "updating" process and model ID
business, have a look at the last chapters of my tutorial here:
https://docs.google.com/Doc?id=dgft4kkq_0f8fd79dh
I can only recommend to store several neighbouring buildings in one
model file and upload them as components if you haven't already done
so. This way, whenever the imagery changes, you can move all models
within a file at the same time and you only have to update the terrain
only once for every file, not once for every building. (Saves some
time.)
P.S. Very nice collection!
Greetings from Weißenburg, Bayern.
Matthias Basler