If you could access the phone but limited by the iCloud account, then just download iMyFone LockWiper and let it do the job for you. All you need to do is to wait for it to complete this task in just minutes.
Step 1. Download and open iMyFone LockWiper. Select “Unlock Apple ID”.
Step 2. Connect your iPhone to computer using a USB cord. Next click “Start to Unlock” to let the process begin.
Step 3. This will automatically start the unlocking process.
Step 4. Wait for a few seconds for process to complete.