IBM ThinkPad T40 series Hardware Maintenance Manual page 141

Removing and replacing a FRU
Make sure that the system lock key A is set to the
Unlock position. Release the front latches in step 4 , and
then remove the top cover 5 . Then detach the connector
cable 6 as in the figure.
5
A
4
6
137
ThinkPad T40, T40p, T41 Series