Blogger do not permit to change your login email address directly. However, there is still a way to change your primary email address. Sometimes, it becomes necessary to update your primary login for your blog.
There are various reasons as to why it becomes necessary to change email address for blogger login.
Possible reasons to change your primary email address
New bloggers usually create their blog with a random email id and later feel that there blog should have been associated with something that looks more genuine. In that case, they have to search for ways to change their primary email address.
When you have more than one blog and these blogs are associated with different email address, it becomes difficult to manage both the accounts. In that case, you want to change the login id of one of the blog so as to manage both blogs from the same dashboard.
You applied to AdSense from another email id and you want your blog to be associated with that email id.
Changing Blogger Login Email Address
I already said, there is no direct way or any account option where you can go and just edit your primary email address. However, you still can do it. Here are the ways:
Login to your Blogger account for which you want to change your login email id.
I assume you already have created another email address which you want to switch to. If not, go and create one first.
Go to Blogger Dashboard > Settings > Basics. In Permissions section, you will find the blog authors.
Click on Add Authors button and send an author invite to the new email address which you want to switch to.
You would have received an author invitation in your second email address. Now, go there and accept it
When the invitation is accepted, you will see the other email address as a new author. Change the role of new email address from Author to Admin
The last step. Login to blogger account from your new created email address. You will see the blog in your dashboard with Admin power. Go to Settings > Basic and remove your old email address from the Blog Authors from Permission.