The biggest thing you can do right now: sweat. Seriously. A lot of weight is water weight. Hit up a sauna, run in sweats, do what it takes to get a good sweat and keep doing it. You don't have to to go into MEPS on the verge of passing out (don't be retarded about it), but just enough to lose weight.

They might have changed things since I went through, but I went through MEPS with a few extra pounds also. If you fail the weigh-in, they'll tape your neck and abdominal regions to check your body fat percentage. Most people who are just a couple pounds overweight will pass the tape just fine, just depends on your body type. There's some old tricks to passing that too if you need them, but like I said with just a few pounds you should be alright (if they haven't changed that).