Loppy
Our Child DLA guides are available from the Guides link at the top of the page.
I'm not aware of a Renewal form and a Google search hasn't uncovered one either so I am not sure how well the guides will fit with the form you have but it is important to remember the assessment criteria, whatever questions are asked, is the same from when you originally applied.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems