Cooker extract hood relocated which trade

I have a wall mounted NEFF cooker hood extractor D69B21N0GB. The hood is 900mm wide by 500mm deep by 250mm high. The extractor fan discharges into a flexible duct leading through the kitchen wall to the fresh air. This flexible duct is concealed behind by a stainless steel faux ‘chimney’ 250mm wide by 170mm deep. The height of the ‘chimney’ is approximately 420mm. I want to raise the cooker hood by about 100mm. This implies that three cooker hood mounting screws and the two fixing screws for the concealed ‘chimney’ mounting bracket will need to be refixed 100mm higher. This being so the ‘chimney will need to be cut to fit the smaller distance between top of the hood and the ceiling soffit. Likewise the flexible extract ducting I expect that the supply lead to extractor fan will need to be shortened. Given above I’m not sure which category of rated people would be best suited to quote and successfully carry out this work. Grateful for the advice of an expert.