Select and purchase the size of reeds necessary to fix the chair seat. Most reeds come in strips that are 1 inch, 2 inches or 3 inches wide. Craft stores typically carry the reeds you will need to fix your chair.
Fill a bucket of water and soak your reeds for at least 20 minutes before attempting to weave them into the seat.
Rid the seat frame of any nails, staples or tacks, along with any reeds that need to be replaced. Sand off any glue spots so you have a smooth finish to work with.
Glue and tape the reed to one side of the chair seat where it needs replacing. Follow the way other reeds are attached to the chair.
Weave the reed through the others to match the pattern previously used to make the entire seat. You may need to turn your chair upside down or tilt it to the side in order to do this. Needle-nosed pliers often make this job easier.
Stretch the reed tightly and attach it to the other side of the seat. Trim away excess reed.
Repeat with any other spots in need of repair in the seat.
Allow to dry. Trim away any loose ends. Stain the entire seat to protect and seal it.