Lenovo ThinkPad R51e Series Hardware Maintenance Manual page 157

(Bottom view)
Step Screw (quantity)
3
M2.5 × 4.8 mm (6)
(continued)
3
ThinkPad R50e, R51e and R52 Series
Removing and replacing a FRU
3
Torque
0.392 Nm
(4 kgfcm)
151