Insert the tip of the right needle into the 4 cable stitches.
Slip these 4 stitches purlwise from the left to the right needle.
Insert the left needle into the first two stitches you slipped... Note: to make a "back cross", insert the left needle into the stitches from behind, through the back loop.
and remove the right needle from all 4 stitches, which will leave two stitches kind of hanging in space. It will be ok.
Reinsert the right needle into those two stitches just hanging there...
Pull your needles apart & insert the tip of the left needle into the stitches on the right needle.
Transfer them back to the left needle. Don't worry if this looks strange.
Knit over those 4 stitches (here I’ve knit two of them)...
...then the rest.
voila!