You can also check out this video on YouTube... not the best quality as far as focus goes, but it shows you how. You do not need the 1/16" roll pin punch, only the 1/8" to get the main roll pin out to remove the sear assembly block.
Also, use the spring from a retractable pen and trim it down a bit rather then buying the "Ace Hardware" spring...
Make sure you click on the webstie link in the description box as it gives a good step by step with pictures.
Will see what I can do to make one with slightly better focus on the small little pieces...