Oh, I wouldn’t doubt there’s plans available on hand to invade, bomb, spy upon, bring brownies and milk to, and generally meddle with every square inch of this planet, under several different conditions.
In fact, I would find it exceedingly amusing if they *didn’t* have a set of plans available for zombie infestation.
If they even have a procedure for alien contact (I’ve seen a (partially blacked out) copy of it), you can be certain they have come up with one for everything equally plausible.

