How to Expunge Records after 8 years?

If your lawyer does not give information at the time of trial that you can ask that a record be expunged and after 8 years you find the item is still on your record and the lawyer stated at the time of trial it may not be expungable what can you do to get it off of your record? The lawyer failed to give all information at the time of the case so your record for all these years has been tainted by one situation that happend over 8 years ago