Let me show you in an example.
First, take the denominator and see how many times it goes in the numerator.
Ex. 13/5
5 goes into 13 2 times.
Then, take that number (in this case 2) and make it your whole number.
Ex. 2 13/5
Finally, multiply the denominator by the number of times it fits into the numerator...
Ex. 5*2=10
...and subtract that from the numerator!
Ex.
13-10=3
Finish it off by putting it together!
Ex. 2 3/5