Knitted purl instead of knit how to correct?

I just started knitting awhile ago and now have started on a hat on circular needles. I noticed that I purled instead of knit and its down about three rows. I have 112 stitches and really don’t want to take it all apart. How do I correct this to make it into knit instead of pearl, only 4 stitches. I hope someone can assist me:knitting:

Watch this video, available on this site under “free videos: tips”, on correcting a stitch without undoing rows.

http://www.knittinghelp.com/videos/knitting-tips

Yes, it’s in the tips section on fixing sts several rows back:

Thank you the video was very helpful