When you start the edging, you've got live stitches on the needle. Cast on 5 stitches at the end of that row. The pattern says to use the backward loop cast on, but I'd probably use knitted or cable cast on (just cause I prefer either of them to backward loop cast on). That needle stays in your left hand. Now start kniting - first you knit 4, then k2tog which is the last of the cast on stiches plus one from the last row of the shawl body. turn your work and continue with the instructions where it says row 1.