manual transmission has two holes, one in top is to used to fill transmission fluid. one in lowest point is to drain.The checking procedure is to open the top nut and stick your finger in there to feel the level of the fluid. The proper level is the fluid right below the fill hole. To fill it, you would need to get Honda MTF fluid and small hand pump to push the fluid up there. The fluid is very thick so do it slowly otherwise the fluid would start flowing out of the hole and you would end up with big clean up job.