Step 1: The first step is to make a sc in the stitch indicated.
Step 2: Next, ch 3 (photo shows a ch-4 but most patterns use only a ch-3).
Step 3: Attach to the sc just made by inserting hook in both the front loop and the left post of the sc. See dotted lines in Step 2 photo as well as below.
Step 4: Complete the sl st by yarning over and pulling a loop through all three loops on hook.
Post-picot: Continue with next stitch indicated in pattern.