i buy from second hand, i cant contact the real owner for his icloud id and password how can i open it?
i call number from iphone contact person, but the number is not use anymore, how can i open my iphone i buy from second hand?
Without that info you will not be able to re-activate this phone. If you can't contact the previous owner or return the phone for a refund, all you'll own is a paperweight.
There is no workaround, & Apple can't/won't help you. This is called Activation Lock. Designed to make lost/stolen iPhones useless.