One step at a time
Future Tense

Subject + Will + not + be + Complement
I               will not  be     a  student
You         will not  be     a  student
He           will not  be    a  student
She         will not  be    a  student
It             will not  be    a  desk
We         will not  be   students
You        will not  be   students
They      will not  be   students
Future Tense
Subject + (Will + not) + be + Complement
I               won't  be     a  student
You         won't  be     a  student
He           won't  be    a  student
She         won't  be    a  student
It             won't  be    a  desk
We         won't  be   students
You        won't  be   students
They      won't  be   students