Remove the upholstery tacks and staples from your chair carefully using a pair of pliers.
Lift the fabric and batting and other material off of your armchair. Do not cut or rip the fabric as it will serve as a template for the new fabric.
Lay the fabric you purchased to recover your chair on a flat surface. Place the first section you removed from your armchair on top of the new fabric. Trace the outline onto the new fabric with tailor's chalk. Cut the new pieces of fabric that will cover your chair.
Place batting over the bare areas of your armchair that will be covered by the new fabric. Pull the batting so it is taut and evenly covers the chair and staple it in place.
Place the new fabric for the back and vertical portion of the chair. Pull the fabric so that it is tight and evenly covers the front of the chair. Staple the fabric starting at the top of back of the chair, working down the sides and finally underneath the seat area. Pull the fabric tight each time.
Place the fabric for the arms and seat of the chair and follow the same process of pulling the fabric tight so it is even. Staple the fabric in place.
Cover the rear of the chair with a single piece of fabric. Create an edge for the rear panel of the fabric by folding a 1/4 inch of fabric underneath the panel and staple the panel in place.
Apply decorative upholstery tacks to cover the staples in areas where they are visible. Add other accents such as piping or buttons depending on your vision for your armchair.