IBM 6648 - Manual (Page 77)

Internal drive removal
Note: The internal drive assembly is designed to latch firmly into place.
When pivoting the drive cage out, you will feel some initial resistance,
so you should pull firmly until the drive cage swings out. Inversely,
when you swing the cage back into the machine case, you should feel a
slight resistance until the cage snaps solidly back into place.
1. Pivot the drive bay cage up and toward the front of the computer.
2. Latch the handle to the front of the chassis, so that the drive cage stays
upright.
3.5
″ drive removal
1. Remove the two screws from the right side of the drive. Lift the drive out.
Note: Be sure to place the 3.5 ″ drive cable under the single tab on the bottom
of the drive cage. Press the cable down so that the cable folds
underneath the drive cage, toward the front of the chassis, instead of
folding back toward the system board. This will ensure the 3.5
″ drive
cable is not pinched when the drive cage is firmly placed into its
horizontal operating position.
Chapter 2. Types 6568/6569/6648/6649 63