That's an easy one, your front brake rotors need to be (turned), its a term used for a way to make your brake rotors perfectly flat again in a machine shop, they are slightly warped so when you apply brakes the high spots on the rotor grabs stronger than the low spots causing a pulsating feeling, its real common, if you could remove the rotors yourself it would cost around $30.00 to fix it, a shop will want I'm guessing $200.00, if you have no knowledge in this field and want to learn you can buy a shop manual for around $10.00 that will give you step by step instructions to do this yourself except for the machine shop work, good luck.