Will this method, wipe out the settings on the router?
No. It will just overwrite the enable password with the new one that you set.
If the device doesn't have "service password-encryption" configured, you can go into enable mode with the above procedure and type "show run", and you will see the current enable password in plain text in the configuration.
Another method if you have a valid username/password but not the enable password is to connect via the web interface and set a new enable password. In most configurations the GUI allows configuration without requiring you to enter the enable password. (This is a security bug in my opinion, but that is the way it is.)