Engine oil & filter change is very straightforward for the M62 engine. The proper filter (LPW500030) costs under a tenner from a LR dealer and includes the big 'O'-ring to seal the filter cap and also a copper washer for the drain plug.
As you unscrew the filter cap (which, let's face it, couldn't have been made any easier to get at) it lifts the filter element (which is clipped to it) and this releases the oil drain valve so the filter bowl is empty by the time you've got the top off. Just make sure you renew the cap 'O'-ring and seat it correctly as leakage from here is not uncommon.
You'll need 8.5 litres of fully synthetic oil. I used Mobil 1 in mine (0W/40) which cost nearly £100 for 2 x 5 litre bottles and which I now regret as the (VANOS) death rattle on engine start is now worse than ever and there's a real 'tappet' noise now that was never there before. I should have used Halfords 5W/40 stuff and saved myself £25 at the same time. Ho hum, we live & learn.