User blog comment:Fujihita/Summer 2017 Event road map/@comment-140.186.96.196-20170822005906/@comment-25637142-20170822061111

You replace those gears with your gears of the same type, of course. Surely, you must have some 35.6cm Twin Gun Mount, 61cm Quadruple (Oxygen) Torpedo Mount and Reppuu lying around, don't you?