Call S&W
Go to Smith and Wesson's website and they will send you one for free.
In the owner's manual.
Steves's pages
Go to Smith and Wesson's website and download/request a manual. Find a bookstore and look for a series of books by J.B. Wood on fireams disassembly.
Standard catalog of Smith and Wesson by supica and nahas
Go the S&W website and request one.
Call Smith and Wesson with the serial number and the will tell you.
You can request or download a manual from the S&W website. If that doesn't work for you, find a good gunsmith.
Contact S&W via their website. If you can't download one they will send you one for free.
Email or call S&W. You can find in online auctions also.
62092
Standard Catalog of Smith and Wesson, 3rd, edition