Lenovo ThinkSystem D4390 Hardware Installation And Maintenance Manual page 32

When the chassis is locked, push the blue release tabs on both sides of the rails.
While pushing down the blue release tabs, continue sliding the chassis into the rack until it is fully recessed.
Tighten chassis with rack by thumb screws (see
during normal operating, and with the shipping screws (see
the chassis in rack.
Figure 2-11: Push chassis into rack
in Figure 2-12: Front bezel screws) on chassis ears
in Figure 2-12: Front bezel screws) if transporting
24