In order to perform basic system maintenance or access the basic system parts (cleaning the system, upgrading internals ect.), it is necessary to dismount the side-pane of the machine. In order to do this slide the computer cover lock to unlock position and then press the cover open button as shown on the picture below:
After removing the cover, you are able to access all the basic internals of the machine or perform a cleanup.
If you need further information on how to dissemble additional parts of the system, please refer to the Y900 RE Hardware Maintenance Manual.