There are too many variables to write it all in a manual and have it work with what everybody has as a kit and how it needs built.
Front end cut off with a bandsaw, or destroyed by a torch?
Replacing the front bushing or rewelding?
Receiver in pieces, in quarters, halves, or whole?
Single piece firing pin, two piece firing pin, spring loaded firing pin?
Bolt hold open?
M53, or MG42, or MG3?
MG3 back end?
MG42 or MG3 recuperator?
M53 or MG42 buffer?
AR or some other trigger system?
What top cover and feed tray?
All of these variations are covered in this website. This is your book.