You can just pick him up with your hands. Probably will be less harmful to it. Turn off your pumps and after acclimation plop him in. Tough little critters.
If he is too skittish to grab with hands or as mine was too strong to get him off the rocks without ripping a leg off I did the bottle trick.
Take a small glass bottle or cup like 2" high. Think bottle size like aspirin or close to that. Then add tank water and a piece of food in it. Put it leaned next to rock work and he will go in and get the food but then cant climb the glass. Worked for me