For the oxidation-number-change method, start with the unbalanced skeleton equation.

Step 1: Assign oxidation numbers to each of the atoms in the equation and write the numbers above the atom.

Step 2: Identify the atoms that are oxidized and those that are reduced. 

Step 3: Use a line to connect the atoms that are undergoing a change in oxidation number.

Step 4: Use coefficients to make the total increase in oxidation number equal to the total decrease in oxidation number.

Step 5: Check the balancing for both atoms and charge. Occasionally, a coefficient may need to be placed in front of a molecular formula that was not involved in the redox process. 

Then you will find that the equation has been balanced.