Task: I want to set all days of the week repeatation in the Morning walk reminder because I don't want to miss any morning walks, and it is good for my health.
Steps:
Click on the Morning walk reminder to view the repeat option
Click on the Tue, Sep 26, 6AM to view the repeat option
Click on the Repeat option 
Click on the drop down button to view the day option
Click on the day option to select day
Click on the Done button at the top right corner of the screen to save the changes in this reminder