Hi John,
You can contact DWP and ask for a 'supersession' of your award. Thus will trigger the whole reassessment process, possibly including a face2face assessment.
The onus will be on you to prove that there has been a deterioration in your condition since you were last assessed and that you now meet the Support Group criteria.
Qualifying for the Support Group If you cannot prove a deterioration you will have to wait for a routine assessment. You can find out when this is due by contacting DWP.
Don't forget that the Decision Maker will be entitled to remove your award, leave it as it is or increase it.