A method of axially separating an annular system, such as a gas turbine engine (10), comprising first (34) and second (36) annular components. An annular array of fastenings (42) couples the first (34) and second (36) components together axially. The first (34) and second (36) components are supported by support tooling. The fastenings (42) are removed to leave one fastening (42) located on each side of the system. One of the remaining fastenings (42) is removed. The relative height of the first (34) and second (36) components is adjusted so that the apertures (46, 48) for the fastening (42) removed at the previous step are aligned. Then the final fastening (42) is removed.