I once had to do the same, and I tried a baited hook, a home made trap, just a small chase. Nothing worked.............
...
UNTIL..
I decided to catch him while he was distracted. While feeding I let the net dangle under the food. When he built up the courage I snagged him. This worked for me, and it was my first fish I ever took back so I followed up with the LFS, and about a week latet the fish was sold.
Something else I heard that works too is during the night scout out his favorite sleeping place. While he is sleeping prepare the area if needed,ie, move a rock or two.
Next turn on your lights, the little bugger will be stunned for a minute and then you move in..
Good luck, and let me know how it turns out.