Will replacing old copied content hurt present rankings?

I have an authority site which I started few years back and i was a noob then and so started to add copied content ..and now its having loads of copied content....its ranked for long tails..the site also got hit in the panda update too...

I wanted to replace the articles with unique content now. Will it be a good move? Or shud i just leave it as it is and let it rank how it is now?

97 views and not even 1 reply?

Content always king, I will suggest you can replace the articles with unique content that's good.