Reusing your old leads will give you a chance to reach out again with a fresh copy and a different approach. Create a new campaign with a new subject line and move already contacted leads (you want to choose the status "Email open, no reply", or "No emails opened").
To reuse your existing leads, please follow the following steps:
Go to the "Leads" tab in your campaign dashboard
Choose a filter for your leads, based on the status
Click on the checkbox and choose "Select all" in this campaign
Click on "Move" to open the drop-down menu and select "To another campaign"
Select the campaign you want to move the leads to or create a new one
Note: Moving leads from one campaign to another will reset their campaign status and history. So only the data (variables) get copied, its status will not be copied.