If pieces of the chair are missing and you do not feel inclined to fabricate new components you may also be interested in StumpChair instead. StumpChair is a simple street art/design project that anyone can do with a few simple tools.
The The instructable for StumpChair can be found here:
Step 1: Chair #1
1) Disassemble the entire chair.
2} Sand the curved parts (they are harder to scrape so sanding is the easier option).
3} Scrape the flat parts.
4) Paint what ever parts you want to be colored.
5) Reassemble the chair.
Step 2: Chair #2
1) Take out the fallen off leg and cut off the dried up glue.
2) Apply glue into the leg holes.
3) Screw the legs back on with short wood screws.
4) Screw the stretcher bars back in place.
Step 3: Chair #3
1) remove the back panel and trace it out on ply wood.
2) Cut out a the replacement back.
3) Drill out the old dowel holes
4) Apply glue in dowel holes.
5) Hammer in new dowels and cut flush with the chair back.
6) Paint the chair.
Step 4: Chair #4
1) Remove the seat by unscrewing it fromt he bottom and remove the old fabric.
2) Cut out the shape of the seat out of the new fabric leaving an approximately two inch border. Staple the fabric oer the seat from the bottom side.
3) Screw the stretcher back in place.
4) Screw the seat back in place.
Step 5: Chair #5
1) trace out the seat shape using a maker and a large sheet of paper.
2) Cut out the paper outline, check it against the seat opening and trace it onto plywood. When checking the fit of the paper make sure that it fits above the seat cavity and will not fall completely though.
3) Cut out the wood shape.
4) Trace the wooden piece onto upholstery foam and cut it out.
5) Staple on new fabric.
6) Screw the new seat onto the chair.
Step 6: Also See StumpChair
See the Instructable here:
The Vimeo movie here:
Or the Facebook here: