I hate to say this Nicole, but your best bet is to lose the weight again.
You can undo the pants- with a seam ripper. And then put them back together- just instead of a 15mm hem give it a 6mm hem.
The problems that you then will have are this- where the seams now meat will be a different colour they wont be faded like the rest of the pants- instant give away -second the button cannot be moved and the fabric for the waist will be insufficient-thirdly, if you look carefully, jeans have a very distinctive cotten that gets used on them. It is much thicker than regular cotton and when you use regular thread on jeans it is instanly visible.
Lose the weight or give them away- sorry:(
Heidi, September 2010