Having done this I should know but can't remember, if you just want to remove the gearbox I think there is no need to remove the mounting though. One thing I would mention is whilst you have access and if it has not been done consider removing the mount and replacing the bearing. It's rarely changed but it does wear, with the shaft in place the inertia of the shaft disguises the wear but once the shaft is out odds on it will feel worn and gritty to rotate.