Lenovo Yoga C640-13IML Hardware Maintenance Manual page 37

"Remove the lower case" on page 28
Step 1. Disconnect the battery pack cables from the system board.
Attention: Use your fingernail to disconnect the cable. Do not pull the cable.
Figure 7. Disconnect the battery cables
Step 2. Disconnect the thermal module cable from the system board.
Figure 8. Disconnect the thermal module cable from the system board
Step 3. Remove five screws.
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Chapter 4 Removing a FRU or CRU
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