I recently went and played on a golf simulator, and found what i thought to be true... I have an over the top swing (out to in 3 degrees or so) on every single swing without fail. As a result I have a wicked slice. I've been playing for about 4 years now and can't seem to fix it. I am a lefty, what are the best ways to try and fix this problem.

I like the 2 ball drill. If you use this for a bit and then can reasonably swing inside the target line, just go to one ball a few feet back on top of the target line. Key point is that you are taking away outside of that ball and swinging down inside of the ball. It's gonna feel pretty different for a bit, let it soak in.