Hello Buell riders: I´m getting ready to change my transmission oil for the first time, I do have a owners manual, it says to replace the gasket on the tranny cover. My question is does anyone else replace the gasket & what´s the process for dumping the tranny fluid and refilling?...& how often should this be done? The only thing I´ve done so far on the bike is clean the air filter and change the oil.