The simplest answer, unfortunately, is that you can't. Apple, for whatever reason, doesn't make a natively compatible iTunes for Linux. But that doesn't mean that it's impossible to run iTunes on Linux. It just means that it's a little harder.
In order to use iTunes on Linux, you'll first need to install WINE, a program that adds a compatibility layers that allows Linux computers to run Windows programs. WINE is a free download available here.
Once WINE is installed, check to see if your version of Linux needs any extras installed to support iTunes or its files.
Then, download a 32-bit Windows version of iTunes from Apple and install it. It will install in the same way as if you were installing it on Windows.
And with that, even though it's not a native version, you'll be running iTunes on Linux.