Experience: Running as a sport has really helped me slim down and tone my thighs. Mix in some weight training to help tone your legs even further, and bulk up your arms just a little to even things out. This exercise is really good for you overall, if you do it right.
Other than toning it up, there's no way you can change your entire body type. Seeing the change after exercise will get you ultra confident though, it did it for me! Learn to love your body; you look great in jeans!
edit: Also, what your doctor means by "body type" is that everyone's bodies stores fat and gets slimmer/thicker in different ways and rates. This also means your bone structure--you naturally have wider hip bones, and that's that. Also, it's nearly impossible to "spot reduce" fat. If you workout, you'll lose all over, and in different places.
Don't expect fat to come off overnight, as this'll always lead to disappointment. Getting the body you want will take a long time, and it'll take work, but in the end, you'll be proud of yourself. All that work will be so worth it!