That's a bonus.
From memory the book time is about 12 hours. But that will be in a fully equipped workshop, by a technician that has done the same job many times.
The box needs removing, so the engine will need supporting. I'd use a support beam placed across the engine bay, which can be adjusted to suit while carrying out the repair. The gearbox is very heavy at about 60kg IIRC, so if you have an engine crane, it's well worth using it to lower the box down, and lift it back into place.
The PTU needs to come off, so the lower ball joints need splitting and hub nuts removed to allow the drive shafts to be removed.
It's prudent to replace wearing items like the clutch while everything is apart, as the law of Sod guarantees that the clutch will fail a few weeks after doing the work.
I'd take the opportunity to replace the drive shaft seals in the box and PTU too, simply because it's easy to do with everything stripped down, and lubricate the PTU splines with Molybdenum grease to reduce fretting.
All these little jobs will add to the time it takes to do the original issue, but will save time and money later on.