Depending on condition 100-200 USD.
You can request a manual at the Smith and Wesson web site.
Smith & Wesson made several different pistols in .45 ACP, including an M1911 pattern pistol. You'd have to be more specific about which model you had in mind before this question could be answered, as the different models vary quite a bit.
Best left to a trained gunsmith
Ask a gunsmith for help
Try egunparts
have a gunsmith show you. less chance of damage.
You can request an owner's manual for free at the S&W website.
http://www.alpharubicon.com/leo/breakdown5906.htm This site shows the field stripping of the 5906 and the 6906 with excellent how-to text and pictures. That's as much as I've found.
Go to Smith and Wesson's website and request a manual. It's free. The instruction manual from S&W that is provided with a gun is not a good reference for taking apart a 3rd gen pistol, especially if you want to go beyond the most basic form of disassembly called field stripping. However... the 3rd gen pistol is not something to be messed around with unless you really know how the internal lockwork functions. It is one of the most complicated in terms of gun timing and relationship of parts. Having said that... there are various videos on youtube that are quite good for learning how to take down a 3rd generation S&W pistol. You can also get information by joining one of the Smith & Wesson internet forums, the best one known, with the largest membership is smith-wessonforum.com
You can request a manual on the S&W website. You can ask a gunsmith for help.
Contact S&W and ask for a manual or find a gunsmith and ask for help.
Best to ask a gunsmith for help. Various models and not all strip the same.