Step 1. Get on your bike and turn it on
Step 2. Lean forward toward the fuel tank (dont sit on it tho)
Step 3. Release the clutch and gun it.
Step 4. Repeat 1,2 and 3
Thatll let you do good enough burn outs in the dirt, if you mean "diggers" or "donuts" then with diggers you hold the from brake in hard and drop the clutch and accelerate fairly hard, this will cause the tires to start digging a whole in the ground.
Donuts are abit harder, do the same as if you were doing a drigger but go easier on the clutch and dont use brakes. I do them by stoppin in 1st and leaning the bike then slowly letting out the clutch while accelerating (if you dont accelerate enough the bike will bog down and stall) and hopping with the leg thats on the ground as the bike rotates.
"Burn outs" and "diggers" are pretty easy but doing donuts will take abit more practice. Just remember not to crank the throttle to hard our i may well end up on your ass.
Hope that helps,
Mazza