How to create an iCloud account and Apple Store id for a phone that had already another iCloud a Apple Store id

This is an iPhone 6. 10.2.1 version Model: MG3A2CL/A

I have 2 phones with 2 different numbers ,and I would like to unbind one of them from the iCloud and create another iCloud account for it. I could unbind them from iCloud, but now I don't know how to create another iCloud account for it and another Apple Store id . Thank you !