Tom- Are they going in and out the Fill tube at all? Cap the tube. If so, here is something I did back years ago. Take screen and make a funnel with just a big enough hole for them to get out and place it over the hole. Have a hive right next to them with comb frames of you have any. Most of the time they will just cluster near the screen. Once you have most of them out you can put them in the hive and then maybe cut the tank to get any remaining bees and the queen if she didn't come out. Make sure you cap the hole so they don't go back in... and remove the tank away from the hive. Leaving the hive there, that will get any bees that are out and any that leave the tank to go in the hive.
To late to do it this year I would think... at least here.
"Where wisdom is called for, force is of little use."
Herodotus (circa 485-425 BC), Greek Historian