A method is provided for disassembling a gas turbine engine. The gas turbine engine includes a compressor section, a combustor section, a turbine section, a static structure and a bypass duct. The static structure houses and supports the compressor section, the combustor section and the turbine section. The static structure includes a turbine support structure. The bypass duct includes an inner duct wall, an outer duct wall and a bypass flowpath formed radially between the inner duct wall and the outer duct wall. The outer duct wall extends axially along the static structure and overlaps the turbine support structure. During the method, the turbine support structure is removed from the gas turbine engine while the outer duct wall remains installed.