It shows different types of blogs to change blogger admin email id.Select first on that gives you very easy to follow instructions and which you have done and I also explain you how to change admin email id in blogger.
I will explain in step by step process for your easy understand.
First of all, go to google search for blogger and log in with your blogger account and once your blogger page is opened. I will paste screenshots for what I am doing this and you can understand easier you can see that step by step images.
Select your blog which blog change admin email id.You have different types of a blog to do and select one blog to change admin id go to settings on that blog.
In settings, it shows different options you go to search for Permissions it's easy to identify because of it in the third main option in that page.
Click the add authors you can add your another email id to change admin id to that email id.Click on invite authors it sends you invitation mail to your new Email account.
Now go to your Gmail account you can see that invitation mail is in your inbox.Open the mail it shows sign in your blog in that new mail click on the caption and signs in with your new mail account that is which authors to add in your previous blog. After sign in click on accept the invitation, it shows your blogger profile associated with your new mail account just click continue to blogger.