GOTCHA... GOTCHA...
You need a small syringe with a nice tapered tip, as mentioned above. The one that comes with Joe's Juice works well too, but isn't as long as the ones I got from the dentist/drugstore.
Then you turn off your pumps, and either feed them a glob of the Juice from the supplied syringe, or use boiling hot water. With the Juice, they seem to recognize it as food and take it in - then they sort of melt and die.
With the boiling water, they shrink away -duh- but if you can get a good look at their little cranny, and get the syringe tip right in there, then just keep it coming until you've emptied the syringe right into the hole. Do another if needed - heck, do three...
Take care not to damage anything nearby. Either method has worked for me, but the boiled ones never came back. A few of the Juiced ones came back (for me).
Try not to get the Juice or the hot-hot water on much else, as they certainly can harm other living things.