How to take apart a multi-colored pen of the sort that's pictured

As you can see, I am capable of dismantling a multi-colored pen of that kind. What I do is first I unscrew the back. Then I unscrew the tip. Then I bring out the gray piece that connects the four ink cartridges. Then I take out the springs from the ink cartridges. After that, I take out the four ink cartridges and it's done :)

--Sam