On a Legend, the 1st & 5th port on each MLX (or ATL) card can be Operators.
If this is not the VERY FIRST MLX port in the system, you can turn off the OPERATOR function by using the PROGRAMMING CONSOLE, (Usually the MAIN ATTENDANT Console).
First, determine the Extension Number involved.
Understand, changing an OPERATOR POSITION (or in this case, deleting one) requires the system to be IDLE.
When you start doing what's shown below, the SYSTEM WILL TELL YOU IF SOMEONE IS ON THE PHONE, AND, once everyone is off the IT WILL FORCE THE SYSTEM TO BE IDLE< NO CALLS IN OR OUT (Ringing Calls will keep the FORCED IDLE from Happening as well...)
So, when it's a nice quiet time, like a the end of the day, DO THIS:
Go to System Program> Exit> Operator> Positions> Direct Line (Assuming it is a DIRECT LINE CONSOLE) Enter the EXTENSION NUMBER and then press DELETE.
Don't Stop There -
One more step to make this work is you must now press:
STORE ALL
At this point the system will RESTART.