Visit your bank or credit union. Because a student loan check is typically a fairly large amount it is important to go to a bank you are a member of. Many banks do not cash large checks for individuals they do not know (as it is easy to deposit a fake check and split with the money).
Sign the back of the student loan check and give it to the bank teller with your bank identification.
Ask for the check to be cashed. Due to the large amount you may be asked if you want to place any of it in your banking account. Turn this offer down.
Sign the receipt stating you received your entire student loan payment in cash.