LX665 Gear box oil drain location

[Jsp7908]

I'm going over a friends New Holland LX665 skid steer for them. The gear oil in the gear boxes under the seats is in desperate need of being replaced. But I haven't been able to find where to drain the oil from the gear boxes. Does anyone out there know? Thank you, Josh

 

[jerry]

The operators manual shows only a fill point ,does not show a drain on those gearboxes. Fill with 80-9o gear oil. is The oil in them contaminated?