I bought a JP trigger to replace the pretty heavy stock one on my M&P15T.
I read through the docs before I bought it, and it looked pretty simple to install. After watching the video, though, it looks a tad more complicated; not so much the driving out of pins and adjustment of allen screws, but the metal removal involved in the disconnector timing and the fitting for the safety involves tools I don't have.
The included video recommends using a bench sander (which I don't have) for these operations. Will ordinary stones work for this? I don't mind investing in a couple of them.
Because JP is located in town, I can ship the lower to them for about $6 and get it back in a week and know it was done "right", although the idea of doing it myself is appealing, if anything to see what's involved. Its probably a dead even exchange in terms of money, with the stones probably being a little cheaper.
I'm pretty mechanically inclined (I load for 6 handgun calibers on a Dillon 650), so it can't be that difficult for me, but I'd hate to fsck it up and need to buy another trigger...