In order to update this, you will need to delete your old feed and add your new one. To delete your feed, go to your Feeds, tab, click on the Feed, and click Delete.
Once you've completed this step, you will need to set up your new feed. To do this, follow the steps below:
1) Click Add New Feed
2) Enter your Feed URL and once the Connect button appears, click this
3) Configure your first post settings
4) Click on the Social Media Accounts to which you'd like to post
5) Click on Start Posting