I once had three golden algea eaters I had to take from a planted tank. I waited until they came up to the front of the tank. Then lowered the net into the water and BAAM! I put the net to the glass with the fish inside.
Easy. Just toss in a juvi pike cichlid. They'll be gone in 2 days. Then to get the pike out, simply add some small PVC sections, the pike will use them as hiding places. Act like you are going to net it and it hides in the pipe, net 1 end while covering the other side eith yer hand,and youve caught the pike in a handsome carrying case.