ive had a look this morning in the light, but i still can't really see anything

its really tricky to look under the inlet manifold, ive tried using a little mirror, etc but its all pretty oily under there so its hard to say where its coming from.....how would i go about removing the oil feed with the engine in the car? i'm gussing i'll have to take the oil filter off....
heres a little pic of the starter with a little oil resivoir on top of it, the oil's pissed everywhere, all down the chassis/inner wing, etc
also the snapped head bolt is on the other side of the head so i would have expected that side to go first?