Start by clicking on 'Campaigns' in the left-hand navigation menu. This action will direct you to the campaign management screen.
From the list of campaigns on the management screen, locate the campaign you want to edit. Next to each campaign, you will find an 'Edit' icon. Click on this icon to open the campaign editor.
In the edit campaign screen, where you see the name, make any changes you feel necessary
Here you can edit the existing products in the campaign, and add new products to the campaign.
Once you are satisfied with the changes you've made, navigate back to the campaign management screen and click 'Publish Changes.' This will make your edited campaign live.