Lenovo N300 All-In-One Lenovo - Manual (Page 19)

Step 4. The rear cover is pinned to the front bezel, use a flat head screw driver work around the edge
to loose it.
Step 5. Lift the rear cover from the bottom edge as shown.
Step 6. Disconnect the function board cable, then separate the rear cover from the front bezel.
Step 7. To reattach the rear cover:
a. Line up the rear cover with the front bezel and reconnect the function board cable.
b. Line up the holes on the rear cover with mounting pins on the front bezel, and place the rear
cover into position.
Replacing the battery
Note: Turn off the computer and wait 3 to 5 minutes to let it cool down before removing the base cover.
To replace the battery:
Chapter 4 . Replacing hardware 13