Hi, JTT-
There are any number of sound editing pckages that will do the trick for you (and help you record LPs to CD, and all sorts of stuff). I've had good luck with packages from Roxio and Magix. Sound Forge worked pretty well for me, too. Sound Forge came free on a Sony computer, and I got big rebates on the Roxio and Magix packages.
In other words, they're cheap.
There may also be a freeware program you can download, but I'm not really familiar with freeware.
-Joe-