Most of the oil will have already returned to the pan through return passageways built into the head. Unless something's seriously plugged you won't make a mess by removing it. When you get it off it's pretty obvious where the oil runs to & drains out.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.