I've shopped White Water a couple of times. While I don't like doing it, it was not really difficult - just a little slow and time consuming. It just requires organization, and a lot of space to place the removed parts. The manual provides a general order of ramp removal.
No matter what game, it's important to take time labeling and documenting everything (place items in separate freezer bags with hardware as you go, and mark them in numeric order). The time you spend on the removal will save you time and frustration when putting it back together.
The key is organization and plenty of space before you start. And take pictures as you go. Super helpful later.