Tohatsu 4 Stroke MFS 2/2.5/3.5A Outboards Service Manual, Page 120Get this manual
3Inspection Item 1) Draining Gear Oil
12Set outboard motor verticalRemove oil plugs and then to drain gear oilRefer to "Replacement of Gear Oil" in Chapter 3Remove lower oil plug first
3 Gasket
Do not reuse