There is no way for an admin or anyone else in the entire world other than someone who knows the current password to change the password.
If you kept your password a secret, then no one else in the entire world has access to the funds in your blockchain wallet.
How can anyone trust you after this?
You can check the source code of blockchain.info and see yourself. If the code isn't modified by purpose, owners of the site are not able to see your password.