However, modifying your player is not illegal . There are no laws against it, at least not in Europe. In the USA the US Digital Millenium Copyright Act possibly forbids defeating region coding. I am not sure, so please check with your local government before using any of these patches. The region code is contained in one byte of which only the first six bits are used.
Region checking The dvd player checks the regional coding of the dvd disc.
If the region code of the player and of the disc match, the player plays the disc. Let's discuss these two methods of circumventing region protection in dvd. In the root of every dvd video discs there is a file called video.ifo that holds key information on the disc. The region code of the disc is among this information. Video.ifo is read at disc spin up.