Firstly get a letter from the Debt management company that the debt has now been 'paid in full and final settlement'.
you have to pay to get a certificate of satisfaction. this costs �10.00 and has to be obtained from the court where the judgement was made.
Once you have the certifcate of satosfaction ,you should then contact the three major credit reference agencies and make them aware that the judgement has been satisfied and provide them with copies of the cerificate so that records can then be updated.
All the best