How to unlock iphone 4 T-mobile?

I have an iphone 4 T-mobile uk company but it's locked, its version is 5.0.1 and baseband is 4.11.8
like so. I tried to unlock it with SAM but i could not. So how can i unlock iphone 4 freely… Please help me…

Just download a software and find something that is easy. I've done unlocking my phone and found one that actually works safely and easy process.