IBM Power System 9040-MR9 Manual page 64

Figure 51. Lowering the removal tool onto the system processor module
c) With the removal tool sitting on top of the system processor module, push down on the ring (A)
slightly so that the blue tabs (B) snap outward and the jaws engage with the system processor
module (C) as shown in the following figure.
Make sure that both of the tool jaws are locked onto the system processor module by pushing
down on the tool.
Important: Do not press the blue release tabs until directed to do so later.
50 Power Systems: System backplane