Lenovo 3000 H220 Hardware Maintenance Manual page 52

Note:
For this procedure, it helps to lay the computer on its side.
2. Locate the memory module connectors. Refer to "Locating
components".
3. Remove the memory module being replaced by opening the retaining
clips as shown.
4. Position the new memory module over the memory connector. Make
sure the notch on the memory aligns correctly with the connector
key on the system board. Push the memory module straight down
into the connector until the retaining clips close.
5. Refer to the "Completing the installation".
Chapter 7. Replacing hardware
49