It is an arse of a job to be sure. Did mine a while back and as I couldn't get the viscous fan off I removed the intercooler, radiator shroud (breaking a mounting lug in the process) the radiator and moved the engine oil cooler out of the way. Then there are a few pipes to remove and you can finally access it. Putting it all back together is even more difficult.
I'd give yourself a good 4-6 hours.