How do I change brake fluid in a dirt bike?

have good supply of new correct brake fluid on hand easiest way to change fluid it to open bleeder valve on brake. fluid will run out die to gravity keep reservoir topped up till new fluid runs out of bleeder, tighten bleeder, make sure reservoir is at correct level, replace cap. do this to both wheels , one at a time .

The answer above is a brief summary of how to do this but for a thorough explanation see the link below