Dont understand knitting instruction

Hi there,
I hope someone can help me decipher this instruction. I am this far away from completing the garment. It is the final shaping of a sleeve. It reads as follows

Slipping first st of each cast off group (cast off 2 sts at beg and work skpo at end of next row, then cast off 2 sts at beg and work p2tog at end of foll row) 7 times
I have 68 sts now and should end up with 26

Can someone please explain?

Welcome to KnittingHelp!
I like to cast off by slipping the first stitch of the cast off. So slip one, k1, pass the first st on the right needle over the second, knit one and again pass the first stitch over the second st on the right needle (the usual pass one over bind off).
Work to two sts before the end of the row and then slip one, k1, pass slip stitch over. This will dec 3 sts per row.
Follow the directions for the purl row (cast off 2sts at the beginning of the row and p2tog at the end of the row).
When you repeat these rows 7 times, you’ll have dec 42sts.
What is it that you’re making?

Thank-you salmonmac for you plain English instructions. It was so simple in the end. I have now completed the cardigan I am making for myself bar the sewing up which I will get round to soon.
Cheers for now Ange:cheering: