iPhone 6s O2 Locked

[FurretMaster290]

I have an iPhone 6s next to me, which is O2 locked. I have never been an O2 customer and probably never will be. Is there anyway to unlock this phone?

p.s I bought this second hand, the person deleted their my o2 account and doesn’t remember the email they used for it

[TallTrees]

Guide: Unlocking an O2 phone to use a different SIM card 

Hello @FurretMaster290 

The above guide may help read carefully. 

Best wishes