Once a creditor has a judgment, they will still have to try to collect on it. Most creditors will use a bank levy or wage garnishment. I don't believe they can take a tax refund unless it is a government agency. But once any refund was in your bank account, it is fair game.
The creditor files for a bank levy or wage garnishment through the courts, so the process will take a bit of time. It will save them (and you, ultimately) money if they don't have to file this, so you should call them and ask to make payment arrangements. If that doesn't work and they end up filing for a bank levy or wage garnishment, there is sometimes a process to list your income/expenses and tell the judge how much of a payment you can afford. It is harder with a bank levy, because once they have a levy and you receive notice, they can usually take the entire amount of the debt from your account. With wage garnishment, the percentage they can take varies by state (in CA it's 25% of net) and the garnishment will continue until the full debt is paid. But as I said, sometimes if you can prove 25% will be a burden, you can get the payment amount lowered.