Have you tried clipping a lightweight leash to the ring of the slip lead and using that to remove the slip lead? It's a management strategy I have had really good luck with on dogs I can't reach towards. I find it works better with a round slip lead than the flatter, lighter ones, but even the flimsy ones can be used. It just means you have to use more force to pull it open again, which can upset some dogs. You put the slip lead on like normal, pulling it to tighten. When you have the dog back in his run, you let go or loosen the slip lead handle while pulling on the clip leash. This should pull the loop back open until you can lift it off over the dog's head.
Here's video I found with a quick Google search: https://www.instagram.com/wolfmotherk9/reel/DDaQtbeylQF/ (Disclaimer: I know nothing about the poster or her other work, so I wouldn't consider this an endorsement of any of her other content! This vid is the only one of hers that I watched.)
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Emme Hones
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