How do I fix the brake lights when they wont turn off?

You have a short to ground somewhere. That is you have a bare wire touching something metal. Is it all three brake lights? The high mount stop light is wired directly to the brake light switch. The other two lower brake lights are wired through the turn signal switch. Hope that helps! Jim

note the diagram. Pull the stop/hazzard fuse, do the stop lamps go out? See the stop switch, upper right in diagram, the orange wire is voltage to the stop switch, hot all the time. Note the white wire, that is voltage from stop lamp switch, when you step on the brake. W/o stepping on the brake, is the white wire, hot, use a test light to check for voltage. If hot, take wiring connector loose from brake switch, is white wire still hot? If so, maybe something wrong with wiring connector or white wire shorted to voltage, somewhere. Just my opinion. good luck