If you loose your private key for your EOS account by any reason, you need to change your key for the EOS account. In my case I forgot to save my private key for my first EOS account in my Scatter setup. If you didn’t save your private key, Scatter never reveal your private key.

First, you need to create one more key in Scatter.

Scatter key pair creattion

This time you have to save your private key in safe place by “Copy” button.

Now, open https://eostoolkit.io/account/permissions and attach your account using “Attach Account” menu in eostoolkit. You need to attach your account as “@owner”.

eostoolkit.io change permission

Now, you may enter your new public key in “Change Permission” dialog and push “Update”. Then you “Accept” your transaction in Scatter. That’s it!