Good luck! Here is an old thread on live traps: https://www.backyardchickens.com/t/232969/modifications-for-standard-havaharts-save-time However, when the "smart" ones show up, I'd suggest keeping a couple of Duke's dog proof traps in reserve:
Yeah, set back to back (rooster in one trap and the other allowing mink to get in to try to get at the rooster. Cover both traps with a section of tarp/black garden fabric/old rugs/sheet. Might take a few nights to get his courage up, but if the mink is hungry it will probably enter the open trap.