The output shaft is the shaft you see at the rear of the tranny when the driveshaft is removed. Just unbolt the driveshaft from the rear end and spin it like that. Try it all ways, in gear and out and try it in all gears. The clutch will have to be pushed in or the tranny won't turn because it will be engaged with the engine unless it's in neutral.

 

Ah, Got cha, so I will need to solicit a helper? How about a hyper 8 year old girly! I will let you know what happens.