Yes, it is also removable. It's described in the instruction manual. First you have to push the selection collar up (or down - I don't know by heart), and then turn it slightly anti-clockwise (I guess a quarter turn or less, it can't be turned any more. Hold the black "joint" at the top, then it's easier to turn) - then you can pull it away downwards. It holds pretty well, you have to pull down harder than you think - and be careful not to hit the bottom when it comes loose.
For the attachment, it's kind of a milled, spiked "L", and on the nozzle a small block, I hope that makes sense, but should then be clear how it should behave ;-)
Hope that helps.