First of all I am not a physician. My first advice is to see your doctor and get his/her permission before you start. Your physician may recommend something different far better for your specific needs.
With that in mind, I think that that the two things one needs to do is :
1. Eat Less.
2. Exercise More.
Lets start with eating less. There are countless diet books with plans you can follow, packaged meals you can buy, and programs you can embark on. My advice is to eat what you are currently eating, just less of it. And much less of foods that you know provide little nutrition but lots of calories. So have smaller portions, especially desserts. Or maybe have smaller portions at meal time followed by fruit rather than ice cream for dessert.
Next, exercise more. I think that a successful exercise program includes aerobic exercise and strength building exercise, but you should start with something aerobic to start getting into the exercise routine. The trick is to find something you can do for 20-30 minutes almost every day and fits your lifestyle. Suppose you work from 9-5 with a 90 minute commute each day, well then maybe you need to find something to do at lunch time. Maybe you get home soon enough to take a nice walk before dinner. Or perhaps, you start late and can get in something in the early morning. Try to find something that does not involve a major investment. Walking and jumping rope are two possibilities. Maybe you can join the Y or a gym for a trial membership. You could have a treadmill or other piece of equipment being used as a clothes hanger.
The hard part is that you need to plan on doing this for the rest of your life. Eating less will happen if you just work at it. Exercise will take finding the exercises that fit into your life and don't get terribly boring. Maybe you could walk with friends, or clean up the old treadmill and put it in front of a TV. Whatever it is you need to find something.
Here is what you need to accomplish the rest of February:
1. Weigh yourself and write it down. I would suggest with light clothes in the morning.
2. See your doctor and tell him/her that you are going to start an exercise program. Follow advice from your doctor.
3. Eat a little less. Do this almost every day.
4. Find one or more aerobic exercises you enjoy and do them for 20 minutes 3 or 4 times a week. If you try something and don't like it, move on and try something else. You don't have to do the same thing each day.