If you do not have a owner's manual, you should get one. You can call Smith and Wesson and they will send you one. You can also check their website and see if one is available for download. I suggest going to a gunsmith and asking for help. You do not want to take the chance of damaging the weapon either mechanically or cosmetically.
Ask a gunsmith for help
Recommend you find a good gunsmith.
Best left to a trained gunsmith. For normal cleaning, no disassembly is needed.
Go to S&W's web site and request a owner's manual. They will send it to you for free.
You can request or download a manual from the S&W website. If that doesn't work for you, find a good gunsmith.
You can get manuals at the Smith and Wesson website.
Best left to a gun smith
it is a Model 39-2 9mm pistol
check out this video: In general, Sigma pistols disassemble like a Glock. http://www.youtube.com/watch?v=O7ws0gAQlpY
Best left to a gunsmith.
You need the help of a gunmsith
Best left to a gunsmith.