I will not get into actual gunsmithing which would require a lathe/mill or any other special machines to accomplish the task.
As stated above, when I finally do get around to making the CD (after I find the kit that I want), it will have everything needed to build/teardown the
AR15. Which would be like barrel installation/removal, rear sight installation/removal/ and so forth.
While having a pre-built upper helps in getting the rifle ready to shoot, it does nothing for learning how to assemble/disassemble that same upper. And that rear A2 sight can be a real bear, even with the special tools to do it.