Hi worrywart
Yes, I would use the letter you used for your MR.
You will need to complete the review form all over again, don't forget to use our guides to help you word the review form.
www.benefitsandwork.co.uk/help-for-claimants/pip#claims One thing you should not do is tick the box stating no change without any explanation. If you need more space to write an answer use extra pages, make sure you add your name and NI number, also number the extra pages.
Gary