Single Crochet Decrease
There are a few ways to eliminate a stitch when working a single crochet fabric. One of the most effective and easiest is the "single crochet decrease." A single crochet decrease is usually abbreviated as "sc dec", but a pattern may also say to "single crochet the next 2 stitches together", aka "sc 2 tog".
A big advantage of the single crochet decrease over simply skipping a stitch (which serves the same purpose of decreasing 1 stitch) is that it doesn't leave a hole in the fabric. That's good news! So here's how you do it...
Insert the hook into the next stitch and yarn over.
Pull a loop through so that there are now two loops on the hook.
Insert the hook into the next stitch and yarn over. Pull a loop through so that there are now 3 loops on the hook.
Yarn over again...
...and pull the loop through all 3 loops on the hook.
And that's all there is to the single crochet decrease!