Study "Assembly.skp" or "Assembly.stl".
Print and assemble all pieces as shown in "Assembly.skp" or "Assembly.stl".
Test fit and trim, file, sand, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. Depending on the colors you chose and your printer settings, more or less trimming, filing and/or sanding will be required.
Assemble as shown in "Assembly.skp" or "Assembly.stl".
I used an indelible ink marker to add the pencil lead effect to the ends of all pencil pieces.
Comment if you have questions.