You should not try to do this without an attorney. there is no new filing fee but you have to put together a Plan and a new means test for the Court, plus any amended schedules that are necessary. The cost will be the payments to the Trustee over a 3-5 year period.
You will not have to file an entirely new petition. There is probably a small fee for conversion, and there will be a fee if you need to add any creditors.
You will need to file some additional paperwork. The easiest way to do that is to get your Plan and any additional local forms filed all at the same time as you file the Conversion.
Your plan payment may include arrears on secured debt, car payments, and some percentage of your unsecured debt as well as trustee fees. The amount paid on your car debt and the amount paid on unsecured debt will be determined using your means test and your Schedules I and J as well as particular facts that will be unique to your case.
Do not guesstimate your Plan payment. Hire an attorney to help you.
If you are being forced to convert by the Trustee or U.S. Trustee due to problems with your Means Test, hire an attorney BEFORE you agree to convert your case. Perhaps the conversion can be avoided with proper counsel.
This response does not form an attorney-client relationship, nor is it intended to be anything other than the educated opinion of the author. It should not be relied upon as legal advice. The response is based on the limited facts provided. Given additional or different facts, the response would change. Attorney is licensed to practice law in the State of California. Responses are based solely on California law unless stated otherwise.
If you convert from Chapter 7 to Chapter 13, on motion of yourself or other party in interest, you may need to update your schedules with accurate information and will need to file a Chapter 13 Plan.
If you did the chapter 7 yourself you really need to meet with a local attorney, they might be able to save your chapter 7 or if needed help you convert it to a 13, they will be able to calculate your 13 plan payment and file any additional documents that are required. A chapter 13 is really not meant for the do-it yourself-er.
For more information, visit www.freebankruptcyinformation.info or checkout my legal guides regarding this topic posted on my AVVO profile.
Legal Information is Not Legal Advice
My answer provides information about the law based on the limited information provided in the questions asked and is not intended to be legal advice. The law differs in each jurisdiction and may be interpreted or applied differently depending on the location or situation. I highly recommend that you consult with an attorney to discuss the specific details of your situation so you can get legal advice tailored to your specific circumstances. The information in my answer is for educational and information purposes only, and is not legal advice or legal opinions. The answer provided to the question asked does not constitute a lawyer-client relationship.