Be careful and don't use a net with a maroon (cheek spines can be damaged and kill the clown).
I have had to catch mine a number of times and I just use a clear container and heard the fish into the container with the handle of a net. My female is large enough to bite hard so I don't use my hand. Usually maroons are aggressive enough that catching them is not a problem. If yours is not, I agree with MandM, don't chase them around, drain the tank.