The detent can usually be strengthened by taking it apart and bending the lockbar in ever so slightly, but this can cause lock stick and impact centering. As for lessening a detent, the easiest way if it's an absolute finger breaker is to just work it in. For frame locks this is easier, you just put a little pressure on the lock and cycle it with 2 hands (one holding the handle, one pinching the blade) checking how it flips every so many (I'd suggest every 10 or so) until the detent lessens. Bear in mind this will increase wear on the detent and could shorten the lifespan of the knife. The other way to decrease the detent that has a fair chance of negatively impacting action is to take the knife apart and bend the lock bar out very little at a time. This can induce lock rock or slip, though, so it isn't recommended unless you know what you are doing.
Another option that's worked for me is to take the knife apart, clean it with some alcohol to remove the factory lube, and add a little of your own higher quality lubricant. Just need a drop or two on both washers/bearing sets and a tiny dab on the detent hole.
The nuclear option, if you are adamantly against sending it in and refuse to live with it and want to risk ruining the knife is to use a drill press and appropriate size bit to very slowly reshape the detent hole, but seriously unless you have moderate machining experience don't do this one.