Nothing silly whatsoever, real easy.
All you need is a thermometer and 12mm hex??? (memory not good on that)
The drain is the 'small' plug on the metal pan, no idea what the humungous one does?
Basically
1. ....engine off
2. Drain box. Refit drain plug!!!
3.Fill new oil (about 4 litres) in through the level plug, which is just above the pan side on the alloy box......... drivers side. One oil overflows stop and fit level plug temporarily.
4. Start engine and run for a bit, using laser thermometer on the box sump or casing wait until you reach 40-45 deg C.
5.With engine running, remove level plug and continue filling until it drips out, that is the fill point.
6. Refit level plug loosely, jump in vehicle and go through tall he gears from PRND, maybe pausing for 3 secs between them.
7. Re-check level, it's correct when temp is correct, engine running and it lightly pours from level plug.
Don't worry about taking a long time to squeeze the last of the oil in, the box won't get hotter than you need.
Drive it.
(Sorry, i'll post back with oil data.)