Well...heck.
You could do what I did, and just give up for the next ten years. But believe me, it's tough to shed 50 or 60 pounds in two months. (Nothing but diet and exercise, thats the good and the bad news).
On the other hand, I would try a reasonable diet and modest exercise. Can you walk at lunch? Then eat food you can take with you, (and just enough to tide you over until dinner). Will your employer install a treadmill or other equipment? Healthy employees don't take as much sick time, and don't die at work as much. It's a good investment for them. Exercise and eat a bit quicker. In the morning, 15 pushups and 25 or 30 situps don't take up much time. Get a pullup bar for a doorway to work different muscles.
Snack on 0 fat stuff, like celery. (Good for the walking lunch, BTW). Don't drink soda pop, or even a lot of fruit juice. The pop will kill you, and juice has a lot of calories. Too many calories in, they don't come out, except in the waist. 8 oz. of V-8 has 35 cals., about as good as it gets, unless you can hack nothing but water. Want some fizz? Club soda. Once in a while, mix it with fruit juice, but watch the juice. Want candy? Eat some, just not the whole bag, bar, or whatever. A little chocolate is good for you. Hard candy lasts longer and has less fat, though, so you can have more of it for the same caloric burn later. Chew gum (I like Carefree cinnamon). Have the guts to throw food away. Quit eating before you feel full. No fast food, no chips, cookies, doughnuts, etc. Sorry. That's just fat you have to burn, or your body WILL store it. I'm not a food Nazi. If I want it, I eat it, just not very much of the bad stuff. Unfortunately, the bad stuff all tastes great, AND is more filling. Discipline. Choose your food vices wisely.
Get one of those hand squeezers. Good for the forearms, and helps you get a better grip on the CCW, too.
Sneak in the exercise where and when you can. Take the stairs instead of the elevator, and other stuff like that. All the pain-in-the-a$$ things almost nobody does. Whoever mentioned taking the kids for a walk (backpack or not) is right on. Kids can give you a great workout.
To do what I did, get up about 3:30 (like me), and get to where you can do 4-5 miles in an hour on the mill (like me), and then you'll get in shape at whatever weight you want (175-184, like me). And your legs and feet will hurt like he-- (like me). But, it has added benefits. My cholesterol was checked three days ago at 141. Tri-G's at 99. Resting at 112/68 or less (depending on time of day, etc.). It would really help if I quit my two-pack-a-day habit and the two drinkies at happy hour, according to my doctor. I'll probably die in a car wreck next week.
Am I a marathoner? Heck no! Can I stay with a 25 or 30 year old? Again, heck no, if I play thier way (which I don't). But in other areas, there are more benefits, if you catch what I mean.
Do what you can, now. It'll be easier to catch back up later.