Q: please i have an iphone 5 which has an icloud on it but i don't the real owner so please what do i do to wipe it out

Sorry but the only way to remove activation lock is to contact the previous owner of this device. Where did you get this phone?

You need to contact the seller and ask him to remove this iPhone from his list of devices. Otherwise, your iPhone will be a useless brick.

Find My iPhone Activation Lock: Removing a device from a previous owner’s account - Apple Support