Q: What if I don't know my previous password to sign out of iCloud?

f your device is signed into an old ID that is an earlier version of the ID you want to sign in with, do the following:

If you are using iMessage and FaceTime, make sure you are signed into these services with your current ID.  If they are signed into the old ID, go to Settings>Messages>Send & Receive and Settings>FaceTime, tap the ID, sign out, then sign back in with your current ID.

Then temporarily recreate the old ID by going to https://appleid.apple.com, click Manage my Apple ID and sign in with your current iCloud ID.  Click edit next to the primary email account, change it back to your old email address and save the change.  (You should not have to verify the old email account so it doesn’t matter if you no longer have access to it.)  Now go to Settings>iCloud, turn off Find My iDevice and enter your current password when prompted (even though it prompts you for the password for your old ID).  Then save any photo stream photos that you wish to keep to your camera roll (unless you are using iCloud Photo Library).  When finished go to Settings>iCloud, tap Sign Out (or Delete Account if you are not running iOS 8) and choose Delete from My iDevice when prompted (your iCloud data will still be in iCloud).  Next, go back to https://appleid.apple.com and change your primary email address back to the way it was.  Now you can go to Settings>iCloud and sign back in with your current iCloud ID and password (your data will download back to your device).

how to activate the phone if the find my iphone is on,without apple id .becouse i bought  a phone from one of my customer ,he erase all the data from the phone but he didn't of the find my iphone option,unfortunatly idont have his any contact details.so if i want activate phone it asking the id and password of the previous owner.if there any solution is there to activate my phone pls help mee i,m trapped actually

Wow thank you so so so so much. I thought I was stuck with my old email that I didn't like, I have changed my name and wanted to change the email and when it all wouldn't work I tried reading things and nothing would help but everything you said helped me out and perfectly fixed it. I appreciate this so so much thank you so so much for taking your time to explain it to help some people out. Then I thought I'd lost all my photo streams (I had a bunch of private ones I hadn't shared with anyone) I hadn't even thought about saving them all to my camera roll to make new streams so when I read that step my heart broke and I went onto my photos and they were all gone and I was devastated. Then I finished the last couple of steps and next time I opened my photos all of the streams were back there. Thanks so so much randers

Huge help, really appreciated. xo

It's asking me to verify my primary email address which I no longer have access to. Any suggestions?