Implementing function with NAND only quickest way
Use the Karnaugh map to create an implementation that uses NOT, OR, and AND gates.

Then, recognize that you can wire a NAND or NOR so you get a NOT function. Use DeMorgan's theory to get an OR function from a NAND or to get an AND function from a NOR. Replace all of the NOT, OR, and AND gates in your circuit with these equivalents.

That should get you pretty far. Come back if you have more specific questions.