What is another way to say do what is needed?
You can always say.....
"finish the requirements"
"do what is asked of you"
"do what is needed to be done"
One of those should work for you
If something is unnecessary, it is unneeded. Another way to say that would be redundant, which means that there is already something else doing what is needed. You could say that expendable or dispensable. You might even say it is beside the point or uncalled-for. Another way of saying this would be to say unwanted.