Unless you have a lot of time and can feed them in a net or more preferably some type of container, and catch them that way, you will have to remove your LR to get them out. Those are the only two ways I have ever caught a fish out of a tank with LR
trap them - with a trap you can purchase online - or.. what I did was empty the entire 55 gallon tank filled with 75 lbs of LR to net one damsel who was terrorizing my tank. You might have to..