Dell PowerVault ML6000 - Manual (Page 267)

Chapter 12 Installing, Removing, and Replacing
Adding 9U Library Expansion Modules to an Existing Library
Dell PowerVault ML6000 User’s Guide 267
5 Open the module’s access door and raise the guide pin by pulling it
up and turning it slightly as if it were a screw. Otherwise, the guide
pin may scratch the front doors of the module beneath it.
6 From the front of the library, slide the entire module toward you and
lift it off of the module below it.
7 Repeat these steps for each module that you need to remove.
1 Guide pin
2 Thumbscrew