[Q] Change Blackphone ROM topic

Hi Everyone,

Recently a friend of mine gave me a Blackphone as a gift.

I realised that in order to fully use this phone i have to subscribe for security apps to vendor. Meanwhile i only use this phone for SMS, voice, games, internet, social media, etc just like my other android 'stock' phone.

If there are anyone who has successfully change the rom of this phone, please shared. I want to change the rom to stock android, CM, or other ROM if possible.

Thanks,
Hikmat.