Step 1: Go to the Schedules Tab
First, click on the Schedules tab
Then click on the Edit button on the -right side.

Step 2: Edit Content
You will be redirected to the Edit Content & Screens, where you can make changes regarding schedules.
(Note:- Remember to click on Save Changes after you edited the schedule.)

Step 2: Edit Screens
In the Screens section, you can add any previously added screen for scheduling.

(Note:- Remember to click on Save Changes after you edited the schedule.)
Video Guide on How To Edit Schedule for Content & Screens