Question [Q] SIM unlock HTC One

I would like to SIM unlock my HTC One which is locked to T-Mobile UK. It is completely stock and has Android OS 4.3 at the moment. I haven't unlocked the boot loader or done S-OFF.

After my search:

I have seen an XDA post for Sim-Unlocking Sprint HTC One but I am not sure if it will work for my HTC One.

Another post on XDA shows methods to SIM Unlock Your HTC ONE M8

An external site has this solution for CDMA variants of HTC One..

Has any one used any of these methods or Is there any similar solution for my phone?

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