Find a sample of a civil complaint on the Internet, write a civil complaint in duplicate, and sign it personally at the witness. Then, make a copy of the IOU and ID card, and bring the bank card or cash 400 yuan (legal fees charged according to the summary procedure) to the court for filing. Then wait for the court to hear the case, and then wait for the verdict.
If the other party does not repay the loan, write an application for enforcement, and then copy the judgment and ID card to apply for enforcement.