It's very simple. ON your return row; knit the first two and last two stitches. Purl the remaining stitches. EXCEPT when you hit the YO's
when you reach a double yarnover, it may be easier if you slip one loop off the needle and treat it as a single stitch. purl into the loop, do NOT slip off left needle; then knit into the same loop.
If you leave both loops on the needle, then purl into the first and knit into the second.