As a bit of a 'time guide', when i re-assembled the whole passenger door, it took about 3 hours - but when i took out the motor to get at some bits I'd forgotten to connect up

and replaced it, it only took about 20 minutes.
It will all depend on if the frame will need much adjustment afterwards to get the glass to fit correctly - i did all of that with mine, and it was fitting and removing washers/shims which took the time to get it right. It's worth doing whilst the door panel is off (if needed).
The glass doesn't need to come out, but if any of the weather strips need doing, then it may have to - likewise if the slider blocks need replacing. It'd be a shame to have to do it all again at a later date - but if it doesn't need it, then it's a bonus!
Assuming the carpet panel on the door will pull away enough to allow access to the fittings, then there is no reason why it shouldn't be a fairly straight-forward job, with both sides easily done in a short day.