Steps for editing an existing campaign:
Navigation: Go to the Campaigns tab in the left navigation menu.
Select Campaign: Select the Pencil/Edit icon for the campaign that you want to edit.
Edit Campaign: Customize your Attribution settings to fit your campaign's goal by selecting which Lookback Window to use and defining the Product Match for both Post-Click and Post-View conversions.
Lookback Window: The Lookback Window is the eligible time period between a sales transaction and an ad event.
Product Match: A Product match is the relationship between the purchased and advertised products.
You can also edit the Campaign Name and Budget per your requirements.
All set: Click Apply and your campaign edits will be applied.