x5 E53 V8 4.4 oil on plugs and in/along plug-coil gallery

[Rantanplan]

Hi everyone,

newbie here sorry..

Changing my 8 spark plugs and found oil inside the spark plug holes and sitting at bottom of spark plug/coil gallery..... this is an "oh dear" I guess.

Could anyone kindly advise me as to where's the oil coming from please?

I've looked at the rubber seal holding down rocker cover and looks good, but obviously can't see all of it due slant angle of V8.

If it is a Rocker cover seal/gasket, does
1) anyone have a engine parts diagram as to what it looks like and a part number for Mister EBay please?

2) Do I need Tom Cruise from Mission Impossible to do it if one wants to do it oneself please, or is it too difficult getting access to all the bolts holding down the rocker cover if that's what it is please?

3) Is there a Mister YouTube who shows how to change rockers cover seal if it is the problem please?

Very warm regards to all you experts

Cheers Mike
Melbourne Australia