Changing the Fluid in your ZA50 is not very difficult. You will need a flat head screw driver and a 22mm socket attached to your favorite ratchet. 1.) You will need to put your puch up on the kickstand or suspend it from a lift. 2.) Remove the Large bolt from the bottom of the motor with your 22mm socket 3.) Grab a smoke or a beer as the fluid drains. 4.) replace the plug in the bottom of your engine 5.) Remove your side cover 6.) remove the rubber plug from the top of the case. 7.) Add around 10 oz. of fluid. (ATF type F is suggested) 8.) Replace the plug in the top of the motor and side cover 9.) Blast and enjoy.