What is the secret to getting these installed..I was putting together my first lower last night and was watching a youtube video for directions. I spent most of my time looking for the dang little retention pin...so what is the trick to getting these things installed?????

If you look in a armorers manual, there is a tool for it, which you can fabricate yourself. Also, you can try rotating the pin slot 180 deg opposite the detent pin, use the pin the push the detent down, and then rotate the pin back into alignment after it is started into the lower.

I use a razor blade to hold the little brass pin down on top of the spring, then push the pivot pin into the hole. It helps to have a third or fourth hand to help.

I have put a few together, and usually use a razor blade also. One of the best things I started doing was to find a large clear plastic bag that I can put the lower and my hands in so when things go flying they won�t go far. Also, I put together a parts kit of little easy to lose things! My third and forth hands are 5&7 years old soooooooooooo....things tend to get lost around here so keep it in the bag!