I feed mine with a turkey baster. I put pe mysis in it and feed him a couple times a week with it. Whenever he sees it he pretty much swims right up to it. Might not be the fastest method but if you don't want to pull everything out could take only a week or two of trying.
A more humane approach, I caught mine by putting a net outside his den and feeding the tank. Bingo-bongo, caught fish. Keep in mind he mit have a back door so seal that up first.
I caught my diamond goby and several other fish by taking a plastic container and putting food at the bottom. When the fish swims in you have enough time to put a net over the opening.
