If you make a mistake in the middle of grafting/kitchener, how can you go back one/two stitches without having to start over again.
It’s not easy ripping back to the mistake and restarting with grafting. It may help to look at the sts in order to figure out where to pick up the pattern. Anything to avoid re-starting.
See if these diagrams help:
I want to add one thing: If you do the grafting with a yarn needle, take of the yarn from it and then take a normal knitting needle to undo with. You undo by lifting up a loop with the knitting needle and then pull out the running end. It is so much easier to undo with a knitting needle as you will not split the yarn. Like that you can undo one stitch at the time until you reach the right point.