Set up RSS on the site

There's a self-written CMS site. It was written a long time ago and RSS was not provided. Now I want this thing to export news to all sorts of RSS feeds like rambler and yandex.

I consulted a friend and he said there was a little work, a day at most. I'll pay 1,000 rubles for the whole job. No prepayment, you can copy the site to your computer and do it there, but until I see the working result - I do not pay anything.