Neck edge decrease total confusion

Pattern wants decrease 1 stitch every row at neck edge
I am knitting two sides separately
Right side is at neck edge so I SSK or knit 2 tog? then knit to end.
Then on purl side I knit to …do I decrease at end ? and how? SSP or p2tog

Left side same question do I reverse

On the purl row, you purl to the last 2 sts before the neck and p2tog. Or SSP. Same thing for the other side of the neck, p2tog or ssp and purl to armhole edge. The p2tog looks like k2tog on the knit side and ssp looks like ssk on the knit side.