Although you have supplied no pertinent information that would be necessary to answer your question accurately, I can at least give you an answer that may be helpful if you want to withdraw your money from a qualified retirement plan.
First, ask your Employer for a copy of the plan's Summary Plan Description ("SPD"). Read the SPD to understand under what circumstances and when a participant may withdraw money from the plan.
Then, if you are eligible to make a withdrawal you will need to ask your Employer for, (1) whatever paperwork you need to fill out, and (2) instructions you must follow, to get your withdrawal. That should be all there is to the process.
You should have an 800 number of the plan provider. See your HR department if you have one.