Find the client in Rosemark and open their profile.  (Pressing CTRL + F is the quickest way to find them!)
In their summary tab, check the “Show All” check box to show all the services this client has received.
Click to highlight the service type you want to start up again.  (If they are starting a service type they’ve never received before you can add it and set it up like you normally would with a new client).
Hop in the schedule manager by clicking the “Schedule” button.
Click the “Service Discontinued” line.
Change the status and add the new schedule!