For smaller fish, they're basically the same as anything else. They don't have any scales or slime for you to worry about but you do have to watch out for their scutes (the white plates on their sides and back). These are a defense for the fish and the smaller the fish, the sharper they are. They have rubbery mouths but no teeth. Just use some pliers and gently unhook them like any other fish. They're a very resiliant fish so if you need to, net them and bring them in your boat to unhook. That'll protect you from possibly falling out and it'll make it easier to avoid cutting yourself on their scutes. I've heard of sturgeon that have been out of the water for almost an hour that were tagged and survived.

For large sturgeon, if you can land them (it might be hard on salmon gear) just bring them along side your boat and roll them over on to their back. They're completely docile in that position. Use your pliers to unhook it or, if the hook is too far in its mouth, just cut the leader. Make sure you roll it back over because sometimes they'll just keep floating belly up.