Before Richard gets too excited ……
There is so little room in a Light 15 or Légère that the gearbox box will not move away enough to clear the sliding splines between inner and outer driveshaft parts.
I seem to recall it is just possible to remove the outer drive shaft from the hub by only undoing the lower swivel and swinging the whole hub assembly up with the top wishbone. However, I would personally opt to remove the gearbox rather than disturb any swivels.
B………….