If you want to do it yourself then you'll need to buy a little device called a 'smart box', actually can't remember the name.... however it will cost u £150.
"smart-clip"
Its an unlock shop sadly (thankfully) there is no free solution to the V3. The earlier ones unlock for around £5-£10. The newer ones can only be unlocked by testpoint and clip. These are gonna hit you for around double that.