I've taken out a 1.25 zetec form a MK4 fiesta as it was knackered, but gearbox was fine. So I sourced an engine that had an auto transmission attached so was going to put the manual gearbox onto the engine to get a working unit (I know i need to put a new bearing on the crankshaft)

However while the manual gearbox has been stored there has been a spill of gearbox oil. According to the haynes there has been no drain plug fitted (what a brilliant idea, Not!) So it's either leaking out of somewhere it's not supposed to or will it be the same fluid and source for where the driveshaft enters the box as some leaked out of there when i seperated them?

If it is the same oil what would be the best way to drain all the oil and then fill it back up?