Pull tight and flip the fish.
HOLWACHAGOT
These are by far my favorite. The longer one in the middle is what i use for everything from billfish,shraks,tuna,grouper,etc. The smaller ones work great for spanish(especially for bait....you don't have to touch them),blues,flounder,trout,and redfish. Just like some of the other guys said,I pull the leader below the fish and pull the fish upwards by the hook and twist. Works everytime. Even on deep hooked fish as long as you can reach the bend of the hook.
To clarify use a little bit, you hold the leader in 1 hand and slide the "J" on the tool down the leader to the hook (or just place it on teh hook shank). When it's in the bend of the hook, lower your hand with the leader and lift with the T-handle. You may need a quick jerk or small shake to allow the fish to fall off.