Make sure the printer is either shut off or completely disconnected from power in order to perform this guide.
Open the door on the front of the finisher that contains the locking mechanism. Then pull the marked handle to the outside which will unhook the finisher from the printer.
Then, gently roll the finisher away from the printer until you see a cable that connects them both. Now, remove this cable by unlocking the mechanism that's located underneath the cable plug connected to the printer.
The finisher is now completely detached from the printer. If you move the finisher around, be careful so that won't tip over since it is very narrow.