At the bottom of the gearbox there will be a plug, if u undo this, the oil will come out. Then somewhere around mid way up the gearbox on the sides, there will be another plug which is where u put the new oil in. Make sure u can get the filler nut undone before draining the fluid. When u undo the bottom nut, wait 10-15 mins for all the shit to clean. Clean botht he nuts when puttin them back in. Goodluck