This video explains how to change a crewmembers status if the crew planning module has not been enabled.
If the crew planning module has been enabled, please see this section of the guide for changing a crewmembers status: https://support.managemyvessel.com/hc/en-us/articles/1500006905081-Approving-and-Adding-Leave-Periods
To change a crew employment status (Crew Planner not activated)
Go to Modules and select Crew Module
Use the left-hand menu to find the crew member you want the status to be changed,
select (…) and then select Toggle Onboard Status.
You will then be able to select the new status then click submit to save.