How to unlock a Windows Phone to any network?

[MilkyTee]

Hey guys, apologies if this has been asked a thousand times.

I've just bought my girlfriend and my mother Lumia 520s (For just 50euros each, new!).

Looking to unlock them to other networks. Where's the best place to do that (ebay etc)? And how much do they generally cost?

Thanks.

 

[N_LaRUE]

This thread has a few different ones. Pick one and go with it.

http://forums.windowscentral.com/nokia-lumia-520/237322-unlocking-service.html

 

[MilkyTee]

Thanks pal.