39407 ÷ 3 = 13135 R2
Alright, let's work through the division of 39407 by 3 step by step.

Step 1:
3 goes into 3 1 times with a remainder of 0.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 3 from 3 to get 0.
Bring next digit (9) of the dividend behind the 0 and repeat the process: 9 / 3

Step 2:
3 goes into 9 3 times with a remainder of 0.
Write down 3 as next digit of of the result. 
Result so far: 13
Subtract 9 from 9 to get 0.
Bring next digit (4) of the dividend behind the 0 and repeat the process: 4 / 3

Step 3:
3 goes into 4 1 times with a remainder of 1.
Write down 1 as next digit of of the result. 
Result so far: 131
Subtract 3 from 4 to get 1.
Bring next digit (0) of the dividend behind the 1 and repeat the process: 10 / 3

Step 4:
3 goes into 10 3 times with a remainder of 1.
Write down 3 as next digit of of the result. 
Result so far: 1313
Subtract 9 from 10 to get 1.
Bring next digit (7) of the dividend behind the 1 and repeat the process: 17 / 3

Step 5:
3 goes into 17 5 times with a remainder of 2.
Write down 5 as next digit of of the result. 
Result so far: 13135
Subtract 15 from 17 to get 2.

The final result is 13135 with a remainder of 2.