It's as easy as installing and configuring the plugin and then creating the override in the a similar way you will do with a template overrides.
If you use it just remember it will not deal with the component use of the data, so you will not be able to add new data in the form if you do not reflect the change in the affected component ;)
After this extension I'm not using spreadsheets anymore, so it's worthed every cent ;)
Last and not least, this extension is not only for being well with Cookie Law, but it also empowers your users and allow them to change their mind regarding cookies. This is a great point if you do respect your users.