You can, as Ethel suggest, apply to have the length of a disqualification reduced, but only if you have been banned for 3 years or more.
However, even if you are successful, the endorsement(s) remain on your licence for the full normal period. That is, they remain �active� for three years (or ten years in the case of certain offences involving alcohol or drugs) and remain on your licence for four and eleven years respectively.
There is no right of appeal either via the courts or the DVLA to have these periods varied.