Best advice: BUY THE KUHNHAUSEN BOOK.
We often get requests like this, followed in a day or so with pleas to give advice on how to get it back together, or questions about why the gun no longer works properly.
The Kuhnhausen book is the best info ever written on the mechanics of the S&W revolver.
I consider it required equipment for any S&W owner, even if you don't intend to open it up.
Just being able to figure out IF your revolver is working properly, and being able to decide if it needs repair is well worth the small price.
In addition, should you decide to do so, the book gives complete instructions on the FACTORY method of doing an action job to give a better trigger pull.
No BS, this is money VERY well spent.
With that said:
To remove the cylinder, remove the screw on the right front of the frame, just above the trigger.
This will either be an ordinary screw or a cap with a spring-loaded plunger under it.
If it's a screw KEEP IT SEPARATE FROM ALL OTHER SCREWS. This screw is a FITTED screw and MUST go back in the same hole.
Getting the WRONG screw in the hole can do serious damage to the gun.
With the screw or cap and plunger removed, turn the revolver over and carefully open the cylinder.
Holding the cylinder steady, pull the cylinder yoke forward and out of the frame and cylinder.
Do not allow the cylinder to move as you pull the yoke out, hold it immovable.