Just keep going business as usual. Given that we have plenty of trilobite fossils from the Cambrian, might even expect future paleontologists to find some fossilized skulls.
The only problem with this is that we might not have long enough for multi-cellular life to recover. While the red giant phase is a long way off, some scientists think that the carbon cycle could shut down as little as 500 million years from now, either due to oceanic evaporation or due to a failure in the weathering process.
http://www.fossilmuseum.net/Paleobiology/CambrianFossils.htm