It is fairly simple....
1.The trunnions and trigger guard on the kit still have the old rivets in, these need to be drilled out. Takes some time, oil, and good drill bits.
2. After the old rivets are removed and the holes of cleaned up, the trunnions need to be installed. I built on a Nodak polish underfolder receiver, the only holes that had to be drilled on the receiver were the ones for the front trunnion. I made a template for these by rubbing a post-it with greasy fingers on the receiver. I then installed the trigger guard, lined up the barrel and front trunnion and tested for mag fit. My front trunnion protrudes from the front of the receiver just a hair, thats where I achieved best lock up/least mag wobble. I marked and positioned my post it template accordingly and drilled each of the 3 holes out with a 1/8 bit. I drilled each hole out progressively bigger, eventually filing to ensure it was lined up with the trunnion hole. I drilled the 3 holes on the left side first and tapped the receiver and trunnion with a 10-32 tap. Installed the button head screws, and then marked the position of the trunnion compared to the receiver on a 2nd post-it. Removed the left side screws and made a second template for the right side holes. Reinstalled the left side screws, and then drilled, filed and tapped the right side. It may have been a little overkill, but I was dead on with my holes, and all this with a hand drill.
3. On tapping the holes, this is probably the hardest part of the whole affair, and again it is not hard but mostly tedious. Lots of cutting oil, going a 1/4 turn at a time and going back, after each complete turn removing the tap and cleaning it. USING NEW GOOD QUALITY TAPS!!!
4. All screws got a healthy dose of red Loc-Tite at the end, after everything was thoroughly cleaned and degreased.
5. The underfolder stock was not hard to install, though it very well may have more moving components than the rest of the AK. Here is a link to instructions with pictures.
http://www.novarata.net/ak-underfolder/AKbuild3.php
6. Weld stock, weld brake, grind down bayo lug.
7. At this point all that needs to be done is install the internals, gas tube, and handguards.
8. I opted to DuraCoat, installed a steel ventilated top cover gas tube, a tri rail lower, and Primary Arms red dot on MI mount. I also did a paracord wrap on the left arm of the stock to provided a cheek weld that wont melt my face in the summer and stick to my face in the winter.
Like I said, this is my first AK build, do not use this as a guide! Check with Bklyn C before doing anything with an AK!
I am typing this on the go, I may have left things out, but it is atleast the general idea.