The first thing you should do is check to see if you have a 2-piece catch, as older guns did not. See this LEM installation guide
for more info. The LEM kit comes with everything you see below (link here
). Even if you don't have a 2-piece catch, you can still upgrade to a 2-piece catch, and install LEM.
When you install LEM, you will lose your decocker. But you get to keep the safety lever if you wish. It will only function as a safety.
If you have any questions, just ask. There are plenty of knowledgeable folks here and they're more than willing to help.