If this was the GPA that was considered, then everyone would get held to a different standard. That's probably why any branch will calculate the GPA themselves so everything is standardized.
For OP, you will probably have to take a ton of classes to pull your GPA back up if you already have a degree. Assuming you have around ~120 credits with a 2.08 GPA, this might take a while. It can't hurt to take more classes and do well in them, but just make sure that you do. Do you have enough time to take so many classes and still stay within the age limit?
Yes, I'm 24. I did the math, it will take 44 hours of A's to get to a 2.5. I have 22 credit hours more left in my degree. On top of that I have to take 22 more and make A's in all to get to the 2.5 minimum.
I can definitely do 22 hours of "BS" classes in one semester and manage A's in all those. So based on that, I'm hoping it takes no longer than 1 semester. I'm planning on taking these at the local community college post graduation for a few reasons:
1) Community college is way cheaper
2) Also I hear much easier
3) Online / evening / weekend classes are readily available