Sony Ericsson K510i

Hi, I need to unlock a Sony Ericsson K510i that is currently locked to Orange. I have the data cable that came with the phone but understand I have to have some kind of software to unlock it myself.

Can anyone help, or offer advice on where to go to have this unlocked.

I phoned a Unlock man who my sister knows and he says he 'should' be able to do it for 'about £20'

Please help!

Jenny