This is the chair before I reupholstered it. You can't really tell from this picture, but the fabric was old and dirty. I removed the seat part of the chair from the frame with a screwdriver. Took all of 30 seconds.
Sorry this is a blurry picture. I just found my digital camera, so the picture quality will improve soon, I promise. No more blackberry shots.
This is the underside of the seat cushion, you can see I have already begun removing the old fabric. I just used a staple remover to get all the old staples out. I cut the new fabric to the dimensions of the chair, plus about 3 inches all around. A good rule of thumb to stapling is to staple one staple in the middle of each side on all 4 sides. This will ensure that the fabric will be taught enough in the middle. You work your staples in a circle, stapling one staple on each side till all the fabric is stapled. (Artists use this trick when stretching canvas).