F6 is the media menu for all modules, and so the same for VDR, but is just basic OSD and channel change at the moment. F7 the normal menu for VDR, but not many of the functions work. There is no basic interface to recordings, etc yet as it is very beta!
I did install VDRadmin, and that gives you an extremely nice interface and full menu options, including extensive video and audio preferences - presumably plugging and activating the normal VDR interface that LMCE doesn't connect through to yet.
That being said - my LMCE box is now screwed! It boots up as if it is a dedicated core, with no Orbiter options, even though the Orbiter  is still in the admin site. Can't work out how to fix it or what caused it - but this happened overnight and I installed vdradmin late last night, so be ware
it may be coincidence (probably) but don't blame me if it does the same to yours..