Improving running times?

[Klompy]

I currently jog a few miles a few times a week pretty much just to clear my mind as I've never been a huge fan of running, but do enjoy the feeling I get after. As someone who can currently run a mile in about 7 minutes (I'm out of shape I know) how hard would it be to improve this time to 6 min within 3 months? What type of training would you do to accomplish this? I just know close to nothing about how to improve running times as I was never in track.