How do you bleed the front brakes on a Honda crf450?

First make sure the fluid is full. Check that the bleeder can be opened. With the bleeder tight, have someone depress the brake and hold it in, you open the bleeder to let the air and fluid out. Close the bleeder and have the person release the brake. Check to make sure brake fluid is topped up, and repeat till all the air is out. Might help to attach a small hose at the end of the bleeder so that the brake fluid drains into a cup.