It's very easy to do if you have a 'ketchup' style squirt bottle that has a spout small enough to go into the fill hole. Get the proper gear oil needed, warm up the trans by running it on the center stand or riding it a while. Remove the bottom drain bolt and let it drain for maybe a half hour if you have the time, replace drain bolt and add the proper amount of gear oil, according to your manual and then bolt the fill hole up and you are ready to go.
Sam:)