How'd he get in there in the first place? If it were me, I'd take my hand and gently slide it under his pod to try and force him off the side of the overflow (I did it to mine when he was on my glass). If you don't want to try it, try sticking a small PH in the overflow and blow it directly on him so he'll release. Once you get him floating, push him into a large Ziplock freezer bag that's full of overflow water (Just keep the Ziplock bag underwater). Take the bag and dump him back into your DT.