Lenovo 3000 C305 All-In-One - Manual (Page 67)

Chapter 7. Replacing hardware
65
Attention
Keep cables clear of the hinges, sides of the computer chassis.
3. Position the computer cover on the chassis so that the tabs on the
cover align with the slots of the chassis.
4. Carefully install the cover as shown, until it securely snaps into place.
5. Install and tighten the six screws on the chassis.