i replaced a full driveshaft on a escort, we didnt drain anything, just took old one off and banged in new one as quick as possible. some oil drained out the driveshaft hole but all was fine
the gearoil comes 1/2 way up the shafts dave, but if you jack the one side of the car up enough, the oil wont piddle out.
and you need to takeout the upper bolt between the knuckle and suspension leg, and slacken the lower of the 2 bolts, the shaft will then "lever" out of the g/box (the inner cv is held in by a snag ring)