As stated build a trap, I built this one which worked very well.
It hangs on the side of my tank and using a long string I can slam down the trap door. It has a feeding hole on the top so I can easily place food inside the trap.
Made catching fish pretty easy for me
The key is to leave the trap in place for a while to gain the trust of the fish, start feeding through the trap and eventually the fish will love going inside, then you pick your moment and bam.