Might as well plan an oil change if you're close to time for it, you don't have to but replacing the brake switch requires removing the right side floorboard and that's a PITA for those that have not done this a lot.
Pull the floorboard, on the brake pedal/master cylinder assembly, you'll see two tiny wires going into it, that's the brake switch. The switch works off fluid pressure so when you remove it, some brake fluid will come out. It won't come shooting out but it will dribble out so have the other switch ready to screw back in quickly. No need to try and do it lickity split fast and goof the threads but be quick about it. Tighten it down firmly and plug it in, pump the rear brakes to get pressure built up.
It's that easy. I didn't have to add any fluid, it only dribbles out.