Motorcycle Repair: primary oil fill, stupid thanks, cometic

Question
how much oil does a 98 fatboy take for the primary?
Where to fill it. I feel very stupid. Thanks

Answer
Remove the primary chain inspection cover (oval cover in center of primary cover).  Drain primary and refill through the inspection hole with 26 oz. of primary chaincase oil.  Always use new inspection cover gasket, new cometic style, HD part #60567-90C at $3.25.  Don't use the older style paper or silicone bead gaskets, they aren't as good.