It's not difficult. Once you order the RAM, look up a tutorial on how to install it on your make/model. As long as you do it carefully, and know how to put it back together after taking it apart (because obviously it goes back together the same way it came apart), you shouldn't have any issues.
For one of my laptops, I usually have like three steps to do: take the communications door off, flip up the clamps for the RAM, and remove it.