The invention relates to a modular device for removing and installing aircraft power plant components comprising a modular frame (41) as main system of the device, common for every component which is to be installed or removed, this modular frame (41) being assembled in attaching points (2,3) of the pylon lugs of the airframe, and this frame (41) comprising: a forward frame (7), at least two lateral frames (8) and a rear structure (9, 10). The invention also relates to a method for installing such a device for removing and installing aircraft power plant components, and to a method for operating said device.