What’s the easiest way to merge existing SharePoint online (o365) accounts with AD accounts when activating ADFS. I need to keep permissions and other account data intact.
So you have some online identities at the moment, that you wish to match up to your on-premises users? In this case, the DirSync tool allows you to soft match based on SMTP addresses. See this article for more info: http://support.microsoft.com/kb/2641663/en-us
Let me know if you need help.