How to re-upholster an office swivel chair:

I just re-upholstered an IBM office swivel chair that had a plastic back and plastic bottom. You could easily find the screws on the bottom (attached to a board that the upholstery is stapled to). the board said Oct. 1983 and it had brown burlap upholstery, changed to sky blue cotton duck fabric with pink butterflies....looks great now. Shock absorber (up and down) still works, but tilt button does not. It did take all day and then some. The back of the chair had two strips of plastic at the base that did not come together and you could flip these from front to back to allow the back post cover of the back to flip up so you could get to the screws to detach the back wooden board from the back plastic. There were also two small screws at the sides under the plastic edge on the sides (just peek under the edging, don't take it all off).On the back there were also two hooks that attached to the plastic back and hooked into the wooden back that the fabric attaches to. You have to pull down on the plastic back after loosening the four screws in the back and the two at the sides under the plastic edging.
The foam was glued to the boards so it had to be scraped /pulled off with a paint scraper , then steel wool, then sandpaper. A hot glue gun comes in handy for re-attaching the new foam,I cut new foam with an electic cutting knife and covered it in polyester batting and white muslin. This was not glued on , but any underneath foam build-up of the edges could be glued with the glue gun.
All office chairs are different, so just have to be persistent and see how it comes apart and put bolts and screws in a zip lock while working. Take the staples out of the fabric with a small screwdriver wedged under the staple and a plyers to pull staples out. Mark fabric taken off with top, bottom, sides, etc with felt pen and use as a pattern for the new fabric. It helps to put the boards, foam and new fabric upside down and kneel on it to squish the foam down while pulling the fabric tight to staple it to board with a staple gun.
I did not find any books on this at library or on internet, so just have to wing it . Best to have two people working on it. If you want a softer seat, maybe don't squish it down as much or use lesser density foam, or if new upholstery is not cushy enough, can also make an extra matching cushion on top of chair. Mine was worth it, just took a lot of work and time and sweat. Cost less than $60 (gave me extra fabric at store).
There is a retrofit available also at http://www.swivel-chair-parts.com/Tips/Retrofit.html (never tried....to change to a wooden bottom). Also saw a parts supplier online (never tried) at http://swivel-chair-parts.com/Contact.html for tilting mechanisms, etc if you want to go that far.