It'* easy. The hardest part is dealing with the smell of the old oil.
On my 92 and 94 SC'*, a 4.5mm allen wrench is needed for the oil plug. Then siphon the old oil out. A baster or something should work to suck it out. Put in fresh oil to the bottom of the treads of the hole. You will need a little more than a bottle, probably. Buy a few extra if you want to flush it with clean oil a time or two.