Under these circumstances, if the defendant got a general release from the jail, it means that charges have not yet been filed against him. This is becoming more common in drunk driving cases, as they sometimes wait to get back the lab results. In that case, when charges are filed, he will either be notified to come in and surrender, or arrested without notice.
If he is still being held in jail, he should appear before a judge, normally within 72 hours, and the judge will set bond. If he gets a personal bond, then he can go home without paying money, but will still have to show up on his next court date. If it is a cash bond or 10% bond, he will have to pay money to get out of jail.
Contact an attorney to defend him if you can afford it, otherwise, the judge will appoint him an attorney while or after he appears in court. Earlier is usually better than later.
Contact me at 248-399-6930 for a free consultation. You and I do not have an attorney-client relationship formed by our communications on this website. Advice given by me on this website is general advice based on partial information. You should not rely on any advice given without first hiring a lawyer in the area where the case is pending, and providing that lawyer with full information.