Enabling / Disabling scheduling for a specific user is easy.

FROM THE WEB APP
Step 1: Go to Settings > Users
Step 2: Click the "This user can be scheduled..." box.
Step 3: Have your team member edit their scheduling availability.
Step 4: Test your team members scheduling rules.
Step 5: Done


FROM THE MOBILE APP
This setting can only be changed by logging into the Web App at this time.