from what i've read - stoning a trigger is probably the worst idea possible for the average DIY'er. very few people have the equipment (or ability) to properly re-harden a trigger to the correct specs for longevity after that modification.
in addition to that, its VERY very easy to over-stone fire controll parts and ruin them due to removing too much material in the wrong place. there's not a whole ton of sear/trigger engagement in the first place so a couple thousandths too much or change the geometry the wrong way and you can toss your stuff in the recycle bin. removing metal is a whole lot easier than putting it back on. you can very easily end up with a trigger kit that will double, triple or even do mag dumps on you. not only is it a safety issue - but if it were to happen at a public range and the RSO is one of the cranky types and calls the authorities, now you've got a serious issue with the BATFE to deal with for being in posession of a illegal NFA item that will take away your firearms owning ability and majorly dent your pocket in the process! going back to my above statement about rehardening - if done incorrectly (or not at all) you can also have parts that wear on you over time that cause the same issues. like TCS said... unless you REALLY know what you're doing modifying trigger engagement surfaces is probably not worth the risk IMHO.
if someone wanted to go the DIY route, probably the best option that i've seen would be to use a pistol grip set screw to remove some of the travel (
get one from joebobs ) and put in a JP yellow trigger spring (and only the trigger spring)(
JoeBob's has that too ) to reduce the trigger pull weight.
its typically recommended to avoid using the yellow JP hammer spring - unless you plan to bob your hammer to reduce the mass. The JP yellow hammer spring is known to not have enough gusto behind it to move a mil spec trigger fast/hard enough for a solid strike and can cause fail to fire issues on (some/many) hard cup nato style primers.
this mod may required threading your pistol grip screw hole the rest of the way through the receiver, but since its already most of the way there, a quick finish with a tap should only take a few mins of your time at most. Even if you have to buy a tap, you're still only going to be at most about $30 into doing these mods.
there's lots of video's on youtube on how to do the trigger adjuster screw mod, here's one to get you started
HTH