Crank out the big flat head fill screw. Found that a wonder bar works awesome. Just the right size. And below, about 6 inches and a little to the left there will be a hex bolt. Crank that lil baby out also. Make sure the bike is level and not on the kick stand. Add fluid till it runs from the hex bolt hole. Use the same oil in your tranny as in your engine. Rule of thumb is never to mix different brands of oil. If in doubt drain ur Hog and fill erĀ“ up fresh. I was lucky enough to still have the original owners manual.