Shards on a Max Champ Question

I have a 3* Rocket and Groot that is max-champed. I have 3k+ shards on them because I can’t figure out a way to open up a dupe without an actual cover. I don’t want to sell the max champ. Is there a way to create a dupe that I’m missing due to a brain hiccup? Or do I really have to wait until I luck into a cover?

If there is a discussion on this already, mods can feel free to post a link and close this thread.

In the Roster page for the character, tap/click the “Stats and More” button down at the very bottom. Then scroll all the way down to the bottom of the window that pops up and there’s a “Recruit Again” button. I just had to find that earlier today for Kamala Khan.

Geeeez. Could they have hidden it in a more out of the way spot?

Thank you!