Easy, right? Well you can learn how to play that pretty well in a few hours on Guitar Hero 3. How long would it take on a real-life, strings and everything guitar? I have no idea. Let's look at one of the many attempts at a guitar tab for this Eric Johnson song.
Crap. It's 8 pages long. Most tabs are 1, maybe 2. Definitely not 8.
|---15'-15-12-14----12-------|-12-----------------12-15-14-12----14-12------|
|----------------15----12-15'|----15-12-----12-15-------------15-------15-12|
|----------------------------|----------14'---------------------------------|
|----------------------------|----------------------------------------------|
|----------------------------|----------------------------------------------|
Oh man, that looks hard. I'm going to practice it, however, and see if I can't at least get the intro going in a week or two. This young kid on YouTube plays a pretty mean version and you can clearly see his hands and follow along I think. Someone else on YouTube told me in a comment that they learned from Jamorama's Lead Guitar package how to play in Eric Johnson style and a bit of Stevie Ray Vaughn.