I just finished most of the lower build and had very few problems, but I do have a question.  

First, just a comment.  I picked up a Yellow Tavern small parts kit when I got the lower, and I have to say that they give you just aboout everything, except extra $&#^! rear takedown detent, which was the first thing I lost.  So the extra $18 didn't help me at all, which was a little frustrating.  I probably missed that tip in a dozen places, but figured I'd mention it.

My question is that the lower assembly instructions on this site state pretty clearly that you ought to get the front pivot pin right the first time, because it's difficult to remove it.  I just know I'm missing something obvious, but don't I need to pull this pin at least partially out to pin the upper and lower together?  I may not have gotten this right, because the pin is IN there, and not moving.  Same question on the rear pin, although that's not an issue until I receive my replacement detent.

Other than that, the instructions on the site, and tips, were excellent and made the process go pretty smoothly.  Thanks, from a new guy!

Which side did you install the pin from?

I installed it so that the head of the pin was on the same side as the spring/detent hole -- as far as I could tell that was the only way it would fit.  I'm looking at the diagram now, looks right.

That is correct. When you say it's "in there", do you mean it won't tap out? Did you use any CLP or other lube?

I got it -- I hadn't used any CLP or anything, and it was a tighter fit than I figured it would be.  I covered the end of the pin and gave it a good whack, and it came out.  Lesson learned on the CLP!  Thanks for the reply.