Just had mine done and aparently there is no drain plug!
And if you are changing the oil you really should do the strainer too (I had a new one fitted).
And yes the cross member does have to come off as well as the exhaust headers (not much fun on a V8 ), luckily mine came off without snapping any of the studs.
Big thanks to Clive and Steve at Bennington Land Rovers, to be honest I had considered doing it myself but when I discovered the amount of work involved I was happy to pay them to do it :D