How do I change my primary email address in Google+?

This form lets you send a request to Google to change your primary mail, although I haven't tested it: https://support.google.com/accounts/bin/request.py?&contact_type=verify_new_email

As of now google policy doesn't allow you to change primary email id. Although you can add other email id. Go to account settings > connected accounts and add other email ids. If you need to change your primary email id , you will have to create another google+ account. Here is good website for most google+ tips http://www.survivalguide4idiots.com

Google account policies suck shit...  I have spent hours on hours trying to rectify my multiple accounts and associated email addresses, and now this has a knock-on affect if you use google open ID to log into other sites...  Google really are shooting themselves in the foot with the way their system works; automatically logging in under different accounts etc.....   its like working with a buggy computer from the 80's again. I can't be the only person that has wasted so much time trying to delete accounts email addresses etc.  and they're too big to realise or get feedback about it!

I dont think you can. You will have to create a different Google+ profile on your other email account.

See https://support.google.com/plus/answer/1045580?hl=en

Wow! Suddenly my account is all under a test email account I created recently. There is literally no way to reverse this...that I can find. I went as far as trying to delete the test email account and ended up deleting years of stuff from my old account name. I was able to recover but will never get those hours back! Help me if you know how.