∞ Upgrading tracks to iTunes Match

Jason Snell at Macworld:

So you’ve bought iTunes Match, which gives you access to shiny new 256kbps AAC versions of your audio files. But by default your iTunes library is still packed with your old files. So how best to upgrade all of those old files, in place, to the new versions?

I tried this on a few songs last night and it worked flawlessly.