you are dropping the 2 yos. so you get to the stitch you want to lead up, you are on RS. before knitting it you make to yo. Pretty much what you do is to store the extra slack (a defined amount) within the 2 yo. Then you knit the stitch that you want to lead up.
When you get to that spot on the WS row, you get to the stitch first, then to the 2 yo, right?
So you SLIP that stitch and THEN DROP the 2YO right away. you keep your working yarn to the WS of the fabric (to the backside, the reverse stochinette side, behind, or as working the WS at this moment: the yarn is between you and your needle when you slip that stitch.
So you now have a slipped stitch that is rather lose and wobbely and does not really belong. But it is there on your needle.
Once you get to it again on RS: it is still too long and awkward. so you just slip it again.
Same on WS.
All slipping with the yarn towards the WS of the fabric and the slipping purlwise.
now comes the big moment of that stitch:
on the next RS: you cable it with the other 2 stitches of that knit rib. Therefore you either put 2 knit stitches on the cable needle (if your long stitch is at the left side of your rib) or you put the long stitch on a cable needle (careful, far too lose, you may drop it).
If your long stitch is the first of that rib: put it onto the cn, knit 2 stitches of the left needle, then knit the long stitch.
If you long stitch is the last of the rib: put 2 stitches on cn, knit the long stitch, knit the 2 stitches of the cn.
So to answer your question: you slip the stitch, you drop the yo and finally you put it onto a seperate needle
Oh, I cable without extra needle.