Uh, respectfully, you don't NEED any of the stuff in the post above. you don't need a double crankset because when you remove the granny gear, you will have created a double crankset. You don't need a new rear derailleur because the rear derailleur doesn't know or care if you have a small chainring (some people would replace it for aesthetic reasons, but it will shift fine). You won't need to touch any of the cables, because you're not going to do anything that affects them.
All you have to do is take off the small ring and turn in the low-gear limit screw on the derailleur so you don't shift off the inside (they're little screws that don't seem to do anything; often one is marked L and the other H. If not, stare at the thing and shift back and forth and see what makes it stop moving).
You'll have to pull the crank to get the ring off, which means you'll need a crank puller plus whatever tool removes your crank fastening bolt. A mechanic could do the whole job in about two minutes, but plan on spending some time figuring everything out A torque wrench for reassembly would be nice, but a lot of us rode and wrenched for years without one.
It's a pretty easy job, but I feel compelled to point out that there's no reason to do it. You don't HAVE to shift onto the small ring if you don't want to, and it doesn't hurt anything being there. You'll save, what, three ounces? And the one day a year you bonk, you won't have a granny gear.