I truly mean it, it's easy. If there is no drywall up, you blow it in like you are spraying a car with a hose. If it's already up, you drill a hole with a drill, then spray it in if you go from the inside, later plugging it up with some compound. If you go at it from the outside, you'll have a little more trouble depending on the siding and how good you are with ladders. The attic itself is the easiest thing of all if you use the recycled news paper stuff. All you do is run the hose up the stairs and yell down to turn the machine on.
It's simply not a very precise matter. If you screw up while doing the walls, you pull some of the insulation out, or if you REALLY mess up and put the drill through both the outer and inner wall, you have 2 holes to patch instead of just the one. But whats one more out of like 500 when you undertake that large of a project?
If you were to only do the attic, that would again be amazingly easy. Like I said, just run the hose upstairs, and pump it full.
Anything and everything you need for that type of project can be easily rented, and the materials easily and cheaply purchased at a home center. I'd even help you get started if you were close by.