Of course it can be done so many ways without buying a program. But to use such a program is easier then to do a lot of operations. You can start Tunebite, let it run in the background, load all the files you want to convert in Windows Media Player and let it do his job. You can go to work or to sleep and it works for you. It needs to do the conversion real-time to keep it's legality, because this way it doesn't harm the DRM protection in any way.
And there is almost no quality loss, cause all this conversion is made inside a codec on the sound card, there are no wires included in this process
Of course you need to be the purchaser of the protected file, it would be at least stupid IMO to share protected files.