A storage library includes cells supported within a frame for holding media elements. A robot assembly is operable for moving toward the cells and manipulating media elements held by the cells. The robot is containable within a module which is removably mountable to the frame to provide modular replacement and removal of the robot from the frame. The robot is contained within the module as the module is mounted to the frame and moves out from the module to move toward the cells and manipulate media elements held by the cells while the module is mounted to the frame. The module is removably dismounted out of the frame while the robot is contained within the module to provide the modular removal of the robot. The module is removably mounted into the frame while a new robot is contained within the module to provide the modular replacement of the robot.