add an optional parameter to Post /updateTicket to remove all secondary assignees using userID 0, and add secondaryassignee using their user ID number.
Example:
adds user by user ID to SecondaryAssignee field in ticket.
("secondaryAssignedUserId","12341234")
removes all users from SecondaryAssignee field in ticket.
("secondaryAssignedUserId","0")
I don't really feel that it needs to accept multiple Id's that would just make it more convoluted we the end dev could just make multiple post requests.