For fines related to a misdemeanor, such as DUI, he can convert the amount he owes to community service ($8.50 per hour, I believe) or jail ($30 per day in Los Angeles County). He can also request an extension of the due date for payment of such fines.
For those fines related to infractions, he cannot convert the fine to jail time, but often he can convert it to community service.
Contact the court to arrange payments. Otherwise contact his attorney to discuss options. Good luck.
This is not intended as legal advice. No attorney / client relationship exists because of this response.
He can potentially convert some if the fines to jail time, community service (possibly) or set up a payment plan. Unfortunately, his license is likely suspense for failure to pay and the hold on his license won't be lifted until he pays it all off.
You're better off borrowing from a friend or family member so you can get your license back than do payments to the court that will hold up your license.
Please pardon any typos - posted via mobile device.
The above answer is for general information only and is based on the information you posted. Every case is fact dependent, so to get a thorough analysis of your situation, you will need to consult face to face with an attorney licensed to practice in the jurisdiction where the incident took place. Do not conclusively rely on any information posted online when deciding what to do about your case.