Enlarging Old Cowboy Hat

I've got a real nice cowboy hat that I've had for 6 or 7 years. I've outgrown it, and was wondering if there is any way to enlarge the band so it will fit. The band is leather, and I'm pretty sure the hat material is cotton.

The hat amterial is probably wool not cotton. The hatband can be split in the back where it is sown together.

So would I just cut the seam and re-sew it farther apart, or just let it rest un-sewed?

If you have a steamer or steam iron, you can do as kevin said and split the leather inner band then steam the wool/felt to reshape it and restitch. They also sell hat stretchers if your interested in going that far. If you don't want to go cutting into it, that may be the way to go. Here's on that's not to expensive on ebay- Hat Form - Hat Stretcher - Hat Shaper - Hat Care cap - eBay (item 370177233918 end time Apr-16-10 04:52:05 PDT)