To the left, to the left! To start, insert your needle into the next stitch as if to knit it, but slide it off without knitting it

Repeat step 1 for the next stitch, so you now have 2 slipped stitches on your right needle.

Now, insert your left needle from left to right through those 2 slipped stitches.

Wrap your yarn and work as if it is a normal knit stitch. Congrats Gang, you have now worked a left-leaning decrease.