Thanks to all on this thread I gathered the courage and change the transmission oil. I used a transmission jack to lift up the transfer case - about 1.5 inches is all you need to get a T40 wrench to loosen the bolts.

I have a question - I did not remove the megatronic, just replaced the oil pan, and filled back about 4.5 liters. After warming up I drove the vehicle and then when I opened the fill plug to recheck the level, oil gushed out and I quickly plugged it back. Does this mean the transmission has enough oil, as I mentioned about 4.5 liters? Appreciate your responses and thank you in anticipation.