How to delete campaign data from Piwik database?

I would like to know if there is a quick way to delete domain specific campaign tracking data from the piwik database (from URLs tagged with UTM/Piwik campaign parameters) without affecting other logged data for the domain?

I have in mind to sell a domain in the future and plan to give the buyer access to a Piwik user account for traffic data but dont want to give away my marketing campaign stats, hence the need to delete that data if it is possible to do by dropping specific table data from the database?