[Plugins: Stats] Can’t change API Key

I want to change the API key for my Blog A to a new one but there is no option for me to do so. I also tried to de-activate, remove and upload the plugin again.

Apparently it is not allow to insert the new API key and prompt me the following error:

Error from last API key attempt:
The owner of that API key is not on the access list for this blog. When this blog was registered, current’s API key was used. To add you to the access list, neverknow1 must visit this blog’s stats dashboard page and use the form at the bottom of that page.

The WordPress.com Stats Plugin is not working because it needs to be linked to a WordPress.com account

Enter your WordPress.com API key to link this blog to your WordPress.com account. Be sure to use your own API key! Using any other key will lock you out of your stats. (Get your key here)

See the screenshot of error here.

I have test the further testing as well by trying to logging in my current WordPress.com account and found out that I have registered the new blog A with this account.

Q1: How do I remove the blog A record with WordPress.com account? (which I can’t find the features, that means once you register your blog, you can remove it. If you know how to do it, please let me know)

Q2: How to change the API key to the new one in Blog A.

Thank you.