I recently took my 2010 Nissan Ultima SL to the mechanic to have an oil change tire rotation and brake inspection. During that trip the mechanic said I was in need of two front tires so I had to replace those as well he also stated the brakes were fine. The next day my abs, vdc and slip lights came on while driving. I got home turned off the car thinking that would just reset the lights. when I tried to start it back up the The brake pedal was rock hard and the car would not start but it filtered through Acc, on and then off. (this car is keyless in order to start it you put your foot on the break and push the start button) I took it back to the mechanic he ran a check on the code it didn't appear to be anything but he cleared the codes out and said come back if they come back on. A few days later I had the exact same issue took it back and he stated it was probably ABS sensor that needed to be replaced It would be a couple hundred dollars. I took it to a different mechanic for a second opinion they stated it was a break lite switch that needed to be replaced. That part also would cost a couple hundred dollars. Oh and my break lights are working properly. My question is would it be easier for me to buy the brake light switch and replace it myself or would you recommend a mechanic.