IBM ThinkPad X21 2660 Hardware Maintenance Manual page 58

When installing: When installing the keyboard, do as
follows:
1. Install the new keyboard, following the directions in
the figure. Make sure that the keyboard edges, shown
in the figure as (A), (B), (C), (D)and (E), are under the
frame.
A
B
C
2. Align the tabs of the keyboard with the corresponding
slots; then press the keyboard until it snaps into
place.
D
E
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ThinkPad X21