Unclenick's post pretty much nailed it. You can re-barrel an action for different cartridges as long as the boltface diameter and cartridge legnth remain the same.
Jim Keenan brought up a very good point though, it would probably be cheaper just to trade it in. Or as Harry suggested, keep it and buy something else. Unless you're a serious DIY'er, or you just really like that rifle, that's the route I would go.