Help with casting on while purling

I am doing a Barbie dress and it is as follows

Cast on 36,
Rib one row,
Purl one row

Armhole shaping:

Row 1: K8 cast off 5 sts., K12, cast off 5 sts. K6

(Here is my problem)
Row 2: P7, cast on 5 sts., P11, cast on 5 sts. P7.

How do I purl on in this situation over these 5 cast off stitches.
Thanks for any help.

You can just use a knit cast on, it won’t show, or you can purl them on - same as a knit but you enter the stitch on the needle purlwise with the yarn in front.

Purl 7 then change the needle with the 7sts from you right hand to you left hand and cast on the 5sts. You can use either a knitted cast on or cable cast on for example (see videos under the Free Videos tab at the top of the page, Cast Ons if you need to). Then transfer the needle back to your right hand and continue with the purl 11. Repeat this for the second cast on of 5sts and again continue with the purl 7sts

Thanks Will give it a try.