Hi,
You can replace a button on a chesterfield sofa by removing the old button-through pulling. Discard it and make a knot of twine on a metal pin. Adjust it on the twine needle and insert it into the sofa. Rotate counterclockwise and remove the twine needle. Install the new button and make knots.

HI,
Numthumb has described it very simply as "how to get the buttons in a Chesterfield sofa".