As said above contact their Adult Social Care team. You don’t needs a referral via the GP, in my experience a lot of GPs have limited knowledge of how ASC works anyway. Before contacting ASC you will need consent from your folks to make a referral.
Anyone over 65 can apply for Attendance Allowance, if both parents have needs they can both apply. Regarding Carer’s Allowance, unless things have changed drastically since I stopped working for ASC 6 months ago you can’t claim if you’re getting a pension. The easiest way to apply for Attendance Allowance is on the http://www.gov.uk website, you can do it all online. Or ring and have the forms posted.