As a minimum, follow all standard on-site policies and procedures for working around operating equipment.
Lock out / Tag out procedures are critical.
In addition, slaked lime can be hot and caustic, so be sure to wear appropriate personal protective equipment (PPE).
Typical appropriate PPE will include eye protection, face shield, gloves and coveralls. In dusty conditions a dust mask, or a half mask respirator, may be required. Make sure to dilute and cool down a slaker before working on any wetted components.