Remove upholstery tacks or staples that secure the existing fabric to the sofa. Insert the jaws of a staple remover under the staples to pry and lift them from the fabric. Collect the staples in a bowl as you continue to remove the fabric. However, skip this step if you're covering the sofa for the first time.
Measure the length and width of the inner and outer back of the sofa, the inner and outer sides, seat and lower front panel. Allow 2 inches for seams before recording the findings. Also measure the length, width and depth of the sofa cushions and record your findings.
Iron the new sofa fabric to remove large folds or creases, if necessary. Spread the fabric wrong-side up on a clean surface. Transfer the measurements for the sofa sections on the fabric, using colored chalk. Cut over the chalk marks using sharp fabric scissors, so the edges are straight and not frayed.
Center and lower the fabric for the back of the sofa on its frame. Tuck the fabric edges under the frame, pulling the fabric taut -- so it covers the back completely and does not feature creases. Insert a row of evenly spaced staples along the lower edge of the fabric to join it to the frame. Pull the fabric taut over the top and insert staples into the padding and frame. Also, insert staples into the fabric at its sides, joining it to the frame directly below.
Center and lower the fabric for the inner back of the sofa and seat pad over the frame. Tuck the edges of the fabric into the sides of the sofa’s frame. Insert a row of evenly spaced staples to secure the upper edge of the fabric to the frame. Brush the fabric with your hands to remove visible creases that form along its front before stapling it to the sides of the frame.
Lay the fabric for the inner and outer sides, and lower the front panel in place -- and then repeat the process of stapling each section until covered. Pull the fabric taut to prevent creases or folds from appearing on the face of the fabric.
Sew fabric cutouts for the front arm panels and upper arm rests to the sofa by hand. Measure the width and length of each section, plus 2 inches for seams, and cut fabric to size. Spread the fabric over the section of the sofa and sew it to the padding, using transparent upholstery thread.
Stitch slipcovers for the easily removable cushions, using a zipper on one side. Sew decorative accents such as tassels along the corners of the cushions or trim along the edges.