HP ProOne 400 G1 All-in-One Hardware Reference Manual page 36

9. Slide the hard drive cage left, and then lift it out of the chassis (2).
Figure 2-28
10. Remove the four mounting screws (1) securing the 3.5-inch hard drive in the hard drive cage. Be
sure to keep the screws together with the blue rubber grommets to use to install a replacement
drive.
11. Slide the 3.5-inch hard drive out of the hard drive cage (2).
Figure 2-29
For instructions on installing a hard drive, see
30 Chapter 2 Hardware repair and upgrade
Removing the hard drive cage
Removing the mounting screws
Installing a hard drive on page 34.