It's pretty simple to change the detent on the manual safety. Pull the slide assy off the frame. remove the rear pin securing the
sear housing block assembly and the manual safety. The detent notch is obvious and deepen this with a very small gunsmith file.
Don't go overboard, you can always go a little deeper, but you can't put it back. My initial estimate was great. Right where I
wanted it. Put it back together and voila, you're in business. If you want a tutorial on the inner workings, or how to, regarding
assembly and disassembly of the M&P there are tutorials on you tube or check out the APEX tutorial that they have on their site.
The APEX's are geared to show installation of their M&P after market add-ons, but provide a great insight to the internals. Their
after market add-ons (of which I have several) are top notch. Always nice to know all you can about the inner workings of your
weapon.