The Idiots Guide sticky will help ... posts 37, 38 and 122. No pictures and not specifically the S but generic enough to give a good basic set of information that will do the job. Really not very difficult if you have stripped a break barrel before. Just take care when removing the trigger block as there may be some preload on the spring. Wear leather gloves and cover the block with an old towel as you release the block from the cylinder. Better safe than sorry.
Cheers, Phil