M&P IL and MS removal and new part install

[number1olddog]

So I ordered a new sear housing block assembly without an internal lock and without a magazine safety. I know that I can take out the old crappy "safety" sear housing block and install this new one and be good to go. My question is, I also ordered a frame key plug to fill the hole but is there a certain way to install this and make sure it stays put and will not fall or come out? I have seen some pics and it looks like it is inserted from the inside because of the bottom disc and how it has to sit against the inside of the receiver. Is this right?

[Irish10]

Thats correct but you may have to work with it a bit as two of mine were a PITA to get in. Once in there held in place by the housing block and aren't going anywhere. Just take your time and you'll be good to go.