Use the File > Geo-location > Add Location command, which allows you to identify a specific locale on Google Earth that you’d like to “bring in” to SU.
SU creates two new layers in your model, one called Google Earth Snapshot and the other called Google Earth Terrain. The former contains a flat photograph, like the view in Google Earth, painted on a face; the latter contains the same photo, except painted on a contoured surface (TIN) representing the actual topography. You can toggle the display between them by checking or unchecking File > Geo-location > Show Terrain, or you can control the layers directly through the Layers dialog.
The photo and the TIN are each inside of a locked group on their respective layers. You can unlock either group, if you wish, and thereupon modify the contents of either. In particular, you can tweak the shape of the terrain or swap the image for another, and so on.
See: [Add Location][1] in the Knowledge Base.
-Gully
Edit: Are you saying you’d like to derive elevation contour lines from the imported topography and export them as a flat contour drawing? That is the opposite of the usual workflow, of course, but do-able.