Dell 8 Owner's Manual page 256

9 To remove a full-height blade system board:
Use the thumb and index fingers of your right hand to lift the system
a
board retention pin. See Figure 3-58.
Keeping the retention pin raised with your index finger, press the
b
corner of the blade chassis with your thumb to slide the system board
out of the open end of the chassis.
Figure 3-58. Removing and Installing a System Board - Full-Height Blades (PowerEdge
M905 Shown)
1
4
3
1 system board
3 tabs on system chassis
256
Installing Blade Components
2
2 system board retention pin
4 slots in system board tray