Noob question, but when I brake from higher speeds (like 45-55) and a good amount of pressure on the pedal I get some pretty bad vibration throughout the car.

I got new front brake pads almost a year ago, put on by a local shop here, but they didn't mention the rotors needing replaced.

I have just had a lot of work done recently so I want to not take it back, but can I assume I have a warped rotor, or worn down rotor... is there any other thing that it could be....

when I softly apply the brakes I get no vibration...

I can get the rotors for about $50 shipped, but is this a job a novice can handle. I have only done brakes once with my Dad, but I have a friend who is more experienced than I am....

__________________
85 300CD Turbo "Das Polluter" 230K sold for $3,000

98 BMW 323is