After the suggested recovery period – or longer if you think you want to fatten up the cat – take it back to where you first trapped it. That's where it came from and where it has a chance to survive if you continue to feed it.
Release it in the evening – it will feel safer in the dark.
Face the door away from you and stand back when you open it for the cat to get out. A tap on the cage/carrier will usually send it out but it might take a minute or two to think about where it is.
Don't relocate the cat to another area – it will be disoriented. Other cats in the vicinity will chase it away, and it could face many other hazards.