First off, kudos on your very realistic goal! Being only a little taller than you, I can tell you that the 160-170 range is a nice, healthy range for someone your height.
I second weight watchers. I’ve used the point system, and I find that it’s an excellent way to educate on portion control and what’s good and bad. Do your research–read EVERY box in the store. I was shocked to see the calorie counts on macaroni and cheese, etc. My first few "healthy" grocery trips took hours. I finally learned to stay away from the middle boxes (except soups) and had to learn to cook everything on my own.
Consider hiring a trainer. Maybe it’s too expensive, but if you can afford it, you might feel more motivated BECAUSE you spent money on it. Or, if your gym is like mine, i get a free training session once a month and they measure my body fat, etc, however often i like. I end up chatting with the guy, too, so he’ll make healthy suggestions (who knew plain oatmeal was such a good for you pre-work out snack?) AND seeing REAL progress in my measurements and body fat numbers. Or, a good realization that i need to work harder.
No more margaritas =]….stick to wine and single liquor mixers with diet sodas if you MUST have a drink. If i’m really watching my weight, i do michelob ultras or waters with twists of lime and lemon. aw , it looks like vodka! sneaky sneaky.
Watch your calories and go to the gym. Lots of cardio to burn off the fat, then weight training to tone up. When i lost a bunch of weight, my trainer told me this schedule:
3 days a week of circuit training weights (so basically it was 50 minutes of weights) with 25 miinutes of interval training (which is awesome at burning fat but so evil….5 minutes warm up, 30 seconds sprint, 60 seconds cool down, repeat, last 5 minutes cool down). it’s rough, but over quick.
On the other days, do 60 minutes of long, slow cardio while watching tv. take one day off recovery and alternate your weight training with long cardio days (which help loosen up your muscles).
Also, i’m sure you know this, but nix any "extras" like soda or chjips that contribute zero nutritional value. Find a calorie count you’re happy with (maybe start with 2000 a day, work down the 1700 a day, maybe 1500 a day for crunch time. i always try to stick to 1500-1700 a day..it forces you to eat healthy snacks like fruit or yogurt) and stick with it! Good luck!