Over half of the track is public road anyway, and will be open for business on Friday (until early Sat I believe). You get to drive the Mulsanne straight (but the chicanes will be fenced off), round Mulsanne corner towards Indianapolis, then past the White House to just below the Porsche curves.
You don't get to drive the pit straight, Dunlop chicance and up to Tetre Rouge. (Check the maps in the Help section for more detail)
Don't go speeding though, le flics are usually in strong attendance.