Flip over the chair and remove the old staples and tacks that are holding on the old leather cover, as well as the buttons that quilt the leather down. Use a staple remover or a flat file to assist in loosening the staples and tacks. Try not to rip the leather during removal.
Mark on the old leather its original placement (right arm, top back) using a grease pencil. This will help you create a pattern. Set the pieces aside.
Use a seam ripper to pull out the old welt cords. Measure the old cords as you remove them. Cut the length of the new welt cord in the same lengths.
Lay the new vinyl or leather upholstery on a flat surface. Place the old leather pieces on top. Trace around each piece onto the new fabric using the grease pencil. Mark the placement of the button holes as well.
Cut out the new leather pieces. Punch clean holes through the buttonholes using a leather punch or awl.
Weave the new lengths of welt cord onto the chair following the original pattern. A curved upholstery needle helps this process.
Tape the new upholstery pieces down into place using the double-sided tape. Attach the replacement buttons now, as it is easier to pull up and reach under the upholstery as you work.
Thread your upholstery needle with upholstery thread. Sew the buttons in place through the foam padding. Tie each off securely and snip off excess thread.
Secure the upholstery pieces in place using the stapler and tacks. Hammer the tacks into the wood frame using the rubber mallet.