As soon as the work at the power plant to decommission Groups 3 and 4 is completed, Armofer repeats the procedure set up to deal with Group 2. The heart of the operation, once the back boiler area is opened, is the gradual lowering of the boiler in stages, from its 53 m to the ground. At +53 m, after sectioning the roof, the rappelling system is mounted, which employs hydraulic jacks for progressive lowering to the ground, sliding within its own steel yoke. To limit weight, the structure is sectioned into two parts, boiler and economizer, proceeding to lower one and the other alternately. Deconstruction then takes place from below, with hot cutting and mechanical demolition by UHD excavators of portions of about 15 m. The cycle is repeated until the rappel is completed. Upon completion, the dismantling of the boiler-castle, from + 53m to +25m with the aid of the crane; from + 25m to the ground with UHD excavators equipped with shears.